Last week, TUAW showed you how to sign iPhone applications for informal developer-to-developer distribution. That approach lets you share applications between members of the iPhone developer program by using your signing credentials to authorize the application for use on your development units.

iPhone applications compiled for the Intel-based simulator can also be shared between developers. And, since the free developer program offers access to the simulator, the apps can be distributed even more widely than with the re-signing approach.

Simulator testing does not offer the full suite of device-specific capabilities. You cannot simulate the onboard camera or retrieve proper accelerometer feedback. The simulator does not vibrate or provide general multitouch input. (You can pinch, but that's about it.)

The strength of simulator-based distribution is that it lets you send out applications for early testing and feedback. Sim-only tests strengthen the preliminary design process; this approach helps solicit feedback on user interface and general program layout before the main development push gets underway.

Simulator-based apps are easy to transfer and easy to use, cutting out a layer of overhead that's needed for when you go to a full ad-hoc beta.

To distribute a simulator application, go to the Library/Application Support/iPhone Simulator/User/Applications/ folder in your home directory. There you'll find the application sandbox folders that are currently installed for your simulator. Each folder is named with a unique id (i.e. 56E66CE5...DC028F) that does not reflect the folder's contents.

You'll have to peek inside to determine which folder is which.The folder contains the application, and three sandbox directories: tmp, Library, and Documents.

To share a simulator folder compiled for 2.2.1 and earlier, you must zip up both the folder with the application and the .sb (sandbox) file that shares the same name as the folder. 3.0 and later applications do not use a .sb file. Just zip up and share the folder.

Install the shared app by decompressing its sandbox folder (and, for 2.x, its .sb file). The recipient must have installed the iPhone SDK. Drop it into the simulator's Applications folder on another machine and launch the simulator. The app should appear in the simulator, ready for testing.

The iPhone Blog is reporting what's purported to be in the next, and hopefully imminent iPhone update to version 3.1. As we've reported, developers were seeded with the beta Tuesday.

Here's the list:

• Voice Control now works over Bluetooth
• Updated AT&T profile to 4.2 (MMS is now enabled)
• Improvements to OpenGL and Quartz.
• iPhone vibrates when moving icons
• Non-destructive video editing means trimming a clip no longer saves over the original video but gives you the option to "Save as copy..."
• APIs to allow third party apps to access videos and edit them.
• Updated modem firmware to 5.08.01

If true, it will put smiles on a lot of iPhone owners' faces. The omission of Bluetooth voice control seemed downright silly. Losing your original video after an edit seemed pretty counter-intuitive as well. It also appears MMS will appear in the update, but that only matters if AT&T turns it on.

No firm dates for the update of course, but if the above is accurate it will be a good one.

Thanks Brad for the tip

Apple has released a 3.1 beta for the iPhone SDK. Both the SDK beta and firmware are available for testing and development to paid members of the iPhone developer program. As pre-release software, any details about this new release remain under NDA.

A pre-installation advisory and beta release notes are available as per Apple's usual release strategy. As before, you cannot use the 3.1 SDK to create applications for submitting to the App Store, so if you plan to download it be prepared to create a separate installation directory.

The new release comes just on the heels of the public 3.0 firmware. Its full-dot-number indicates that it contains more than just minor bug fixes (a relatively minor revision would probably be listed as 3.0.1).

Thanks to everyone who sent this in.

Danielle Cassley and Jason Citron are the folks with their names on Aurora Feint, but as Danielle told us in an interview a while ago, Peter Relan is the real mastermind behind the growing Feint empire. Not only did he put the two together in an idea lab, but he's one of the driving forces behind the OpenFeint enterprise. Under his oversight, the Feint folks have swelled to become one of the major forces behind iPhone gaming (and thus, behind the iPhone's app ecosystem itself).

Netanel "Net" Jacobsson is a newer addition -- he's previously worked with Sony Ericsson on their mobile devices and Facebook on their own growing app empire, and now he's arrived at OpenFeint to help them use the lessons he's learned at the biggest online social networks around on their social software. Get the sense of how big this is yet? Relan, Jacobsen, and Citron all have pretty big ideas about where iPhone gaming is going, and as 3.0 comes down the pike and introduces a whole set of new features from Apple, they're in the best seat they can be in to do exactly what they want to do.

TUAW sat down with the three last week, and chatted about iPhone 3.0 and why it's such a big deal for developers, how they're going to approach microtransactions (carefully), and what's coming next for OpenFeint now that they've rounded up a whole stable full of developers implementing their backbone. Click "read more" to continue.

Have you seen anything like that already, where developers have said, well we thought about doing it this way, but we're going another way?

PR: Too early. The phones aren't even out yet, user experience hasn't occurred yet. I would say July, we'll get a lot of feedback once these games come out with push notifications. The other thing that's kind of interesting, by the way, is that OpenFeint is working on cross-compatibility, because if I have a 2.2 iPhone and you have a 3.0 iPhone, and you send me a social challenge, in my app on 2.2, it won't show up as a push notification, right, because I don't have the 3.0 iPhone. So we are support the concept of push notifications in the plumbing and infrastructure of OpenFeint, however on a 2.2 phone, whenever the user next opens the app, they would see a screen that is an OpenFeint screen that would have a notification saying "you've got to beat my score," as opposed to seeing it on the iPhone icon, as a number, like the Mail thing, where it says you have notes waiting for you.

So I think as a user experience, the jury's still out, because the platforms are just getting ready, right? So the key here is to say that we're going to make it trivial by continuing our tradition, which is no servers, very easy to integrate, and some big games will launch in July with push notifications and then we'll go from there.

I think, to a certain extent, the same thing will happen on the microtransactions side. It already has happened with Xbox Live -- I don't know if you remember the story of horse armor, where everyone says "how can you release a different graphic and ask us to pay for it?" Have you seen examples yet of how developers want to use microtransactions? Are they aware of that danger or are they fearful of that at all?

PR: So I think the obvious one, just because I have, as I said, investments in companies in the Facebook app space, the big reason for microtransactions is virtual goods. So any kind of virtual world, avatar apps, some of these Mafia iMob apps, you can assume that there will be virtual goods unlocking with microtransactions. That one I think will translate over fairly well, in fact Net is going next week to China, where he's a keynote speaker at Tencent's annual conference. Tencent is an Asian company which does a billion dollars in microtransactions, all of it virtual goods. So I think that microtransactions, as we see them on social networks today, will come pretty much that way onto the iPhone social network, or the iPhone gaming network.

NJ: I also think that it will actually lead to the pricing, might even drop dramatically, but those who are charging for applications are going to go free, because they're going to earn much more by making it free and leveraging microtransactions.

Yeah, if you're charging $4 for an app and can sell four levels for $1 each, that's the way to go.

NJ: The user starts playing, gets very engaged, and wants to get to the next level and make the purchase, and it's very difficult not to make the purchase if you're engaged and you want to continue the game.

PR: The thing that's a little trickier, I think, is when you have microtransactions that aren't directly virtual goods, because virtual goods don't fit the theme. But are like chapters, or just additional content in the game. Then, I think, the business model is a little trickier, because that's your content update strategy, and to some extent, the iPhone user is used to -- like, if you look at the success of Pocket God, it's a double edged sword. If you talk to the Pocket God guys, their game is one of the few games that stays in the top five constantly. It's just always in the top five. And they use OpenFeint, and they're going to use push notifications, but when we spoke to him about microtransactions, he said, I have to figure that out, because their commitment to their userbase is, every week you're going to get an update with more content. So given that he's already committed that on the current price point, how does he unlock more content with microtransactions? So he was the first to say I definitely want to do push notifications, but I have to think hard about how I could incorporate microtransactions into Pocket God. So I do think there's a little more complexity there, especially when it's not just direct virtual goods. But I think they'll crack it. I think some other people we're talking to are certainly thinking of Chapter 1, Chapter 2, Chapter 3, three microtransactions. And certainly the virtual goods guys are like no questions how they'll do it.

And there are definitely precedents for both, in terms of episodic gaming on other services. Jason maybe you can talk about this, too, as a developer -- I'm really interested in the balance between making sure that what you're selling people is worth it, or something that's not. If you're asking to pay a dollar for a gun that's just a re-skin, people won't go for that. What do you think of that?

JC: I think, as a game designer, what you have to really think about is the motivations for why people will want to purchase this content. Whether it's a re-skin or not is less important than what it will allow you to do in the game. And the reason why I think virtual goods have done so well on social networks is that social pressure is a huge motivator to getting people to do things, and if part of that social pressure results in you engaging and buying virtual content, people are much more likely to do it. I mean, if you just have another gun that allows you to increase your DPS by two points, that's not terribly interesting to anyone but the ultra hardcore gamer, and then they'll probably just be pissed off that they have to pay for it. So that's not really an appropriate way to go about it. As a traditional gamer, buying episodic content or buying level packs, or substantially new gameplay experience, fits with my head, and then virtual goods, I think, have to be motivated through social pressure.

And the last question I have is just about the future of OpenFeint. I have to give it you guys -- there were quite a few, and there still are, services poking around that want to do the kind of stuff that you're doing. And just in terms of size and influence right now, you're kind of the top of the heap. So what's next, are you planning to kind of sit on the heap and just keep things set, or are you still aiming to improve here?

PR: I think that definitely we will continue to innovate and add more services to the platform -- there's no question that it's a platform play, and that we will continue to add features and additional things. I would say two things: one is, we will publish games, always, on top of our own platform technology, that will really kind of push the borders of gameplay design around the OpenFeint platform, to sort of demostrate and lead the way. So in the last announcement, we did hint at a new game coming out this summer based around push notifications and microtransactions, where we want to lead the industry. Because we never think that by being in front today, that we will be always in front. So we want OpenFeint to be the premiere platform, we agree that today, we certainly feel like it's way up there, but we feel like you constantly have to build new product on top of your platform to really make a world class platform. Because otherwise you're just sort of opining and thinking oh, this is good stuff. So we always want to test our own platform, and expect a title this summer based on OS 3.0 and OpenFeint features.

The second thing, which is, I think we're really doing something different around the business model. Ngmoco announced their Plus+ platform this week, and it's really a publishing tool rather than an open platform, and we're pretty proud of the fact that we're sort of the biggest player who is really able to provide an open platform where a developer does not have to make a publishing deal with us in order to get access to the platform. Ngmoco's platform is hey, we have this platform, it's part of our publishing network, and if you want to publish games with us, that's how you get the platform, and obviously you know the economics of the publishing business in the game industry, right? There's revenue that has to be sacrificed there. So I think as a guiding strategy, we will never make our platform related to anything with our publishing because it's our belief that this OpenFeint thing does two things that we will always have to provide for publishers: no servers, because 90% of developers have no experience building servers, they build great console games, client side stuff, C, C++ programming, all this stuff, but they really don't have any backend experience. And two, we're not going to take rev share, in terms of publishing deals. And those two things, I think, are sort of our long-term guides. The third thing is to build our own games constantly, so we can use Danielle and Jason's game design and knowledge to say here's the kind of games we can do. So if we can do that and execute, I think, with some fingers crossed, with some luck, we'll emerge as the de facto standard, which is our goal.

I had talked to Danielle a little about pricing already, but I wanted to ask about microtransactions as well -- when you do that stuff, are you not skimming off revenue as it comes through, or what is the pricing scheme there?

PR: Well even today, we have cross promotion inside OpenFeint 2, even before microtransactions, where if two players meet in a lobby, and they're from different games, then one player clicks on the other player's game, and you go to the App Store and you buy that other player's game? That's what you call our one-touch iPromote product inside of OpenFeint, it's a big draw for a lot of developers, because our community is now three million and growing -- we call it our social bazaar, because the App Store is so cluttered now that it's hard to differentiate. So you use OpenFeint and get your game in front of three million people in these lobbies. That revenue, when someone buys a game using OpenFeint's cross promotion feature, doesn't come from the developer, it comes from Apple. Because we are an Apple affiliate, through BigShare. So we take the user into a webview, which is our own catalog, where you can buy games off the App Store, and then Apple actually pays us. So that's hopefully -- this is the same thing, the whole idea is to get Apple to pay us every time there's a purchase in the App Store, including in-app purchases, as opposed to the outside.

Great. That's pretty much everything I had to ask, was there anything else you wanted to share? I guess we'll keep an eye on the game coming out this summer.

JC: Yeah, I guess the only other thing worth mentioning is that OpenFeint is available now -- it can be downloaded by anyone from our website. It's real.

Cool. Thanks very much.

With iPhone OS 3.0 only having been released yesterday, two big companies are already angling to be developers' go-to for setting up push notifications and other online services for the new apps. OpenFeint was the first service we've heard about -- they have been offering social networking connections to developers for a while, but with the new firmware release, they tell us that they're also hosting options for both push notifications and microtransactions to their stable of app developers.

That stable includes apps like Pocket God and Aurora Feint (Danielle Cassley of both Aurora Feint and OpenFeint told us a while back that she was very excited at the prospect of microtransactions with 3.0), and both of those games, as well as others on the service, are planning to include push notifications with "social challenges" -- you'll challenge a friend to complete a certain goal in game, and then get notified when they meet that goal. Look for those new features in an OpenFeint app near you.

And OpenFeint isn't the only service jockeying for developers' attention -- Urban Airship is also making a bid to host push notifications for iPhone game developers. They've landed one of the first push-enabled games, Tap Tap Revenge, and are looking to offer push to more devs, along with in-app purchase support as well. They don't quite have the library together that OpenFeint already does, but their service integrates, they say, in just a matter of hours, and their aim is to make it "brain dead easy" for developers.

The floodgates are open, and we're sure to see more and more companies jump in on hosting plans like this in the future. Prepare to be pushed.

Are you an App Store developer? Are you looking to keep track of how your applications are doing from the convenience of your iPhone? The open source AppSales Mobile application has made a place for itself in the developer community, offering up-to date statistics with daily and weekly reports from the iTunes app store. You'll need a developer license to run it, however, as it's not available in the App Store. You must download the source, compile it in Xcode, and install it onto your iPhone.

AppSales Mobile offers an easy-to-use settings page. Just enter your iTunes Connect user ID and password and choose the currency you want to work with (this defaults to the euro, so US devs will probably want to change it to dollars). Return to the main menu and click the refresh button. If you've got a solid network connection, your reports will download in a matter of minutes.

One of the relatively unsung features of the upcoming iPhone 3.0 firmware is that the new version of Safari for iPhone will use geolocation. This means that the browser can request location information from the iPhone's GPS receiver, and can also provide that location information to websites that you're visiting.

ComputerWorld's Seth Weintraub reports that the beta versions of the firmware are working well with sample web-aware websites. This capability is not only planned for the iPhone's implementation of Safari, but many upcoming browsers for Mac as well.

Geolocation capabilities make it simple for developers to create web apps that no longer need to ask you for an address or zip code. Google, for instance, is planning on making their Latitude application a 3.0-only web app rather than a standalone application on the iPhone. Latitude will leverage the geolocation features of Safari by knowing exactly where you are at a particular point in time and sending that info to the Latitude servers, then returning the whereabouts of your friends while informing them where you are.

For those of you who don't want your 3.0-enabled iPhone to let the world know exactly where you are, remember that you can always turn off Location Services in the General Settings or just answer "Don't Allow" when asked if Safari or a particular website would like to use your current location.

Here's a telling sign of the popularity of iPhone development: we posted about an online course being offered by Stanford just a few months ago, and in that time, the course has been downloaded over a million times through iTunes. The director of iTunes U at Apple says this is the fastest any course has ever hit the million mark.

Only those attending Stanford will get credit for completing the 10-week course, but the material is available to the public right there in iTunes. And of course there are lots of ways to learn how to make apps on the iPhone -- Auntie TUAW has answered that question, and we've even got an iPhone Dev 101 series to help you wrap your mind around all of it. The iPhone itself seems made for newbies, and considering that there's apparently lots of money to be had in Ye Olde App Store, it's no surprise that people are flocking in huge numbers to the documentation.

Whether any of those apps are any good, of course, is still up in the air. But who knows -- someone who starts with the free iTunes U course might one day be a game-changing designer. There's got to be at least one winner in those million downloaders, right?

Sure, the transparent email and the yet-another-dialer brigade are all well and good, but there are a few things the iPhone doesn't do that I really wish it would. Here's a pair of app suggestions that are probably outside the bounds of the SDK and prime fodder for jailbreak developers, but if someone came up with a way to do them that would make it onto the App Store, I can guarantee you at least one customer.

WiFi Master: If you use your iPhone in a major metropolitan area, you've probably encountered the problem I have in New York City -- scores of access points named 'linksys,' 'netgear' or 'default' or a Starbucks broadcasting AT&T's WiFi network on every corner. Join one, just once, and your iPhone insists on hopping aboard whenever it's in range, whether or not the named network is the one you meant to use or whether you've signed into the web portal for the WLAN (leaving you starved for connectivity, as the 3G connection is superceded by the WiFi link).

Tweaking the network settings is generally a no-no for non-Apple apps, but we need help. Give me a quick way to turn WiFi on and off from the home screen, a way to exclude or include access points by MAC address instead of just by SSID (locking out the rogue 'linksys' networks), and instant display of my assigned DHCP address without diving four screens down into the Settings app. Granted, the Devicescape sign-on automation apps are a good start towards this goal (the Easy WiFi for AT&T iPhones app is worth the $0.99 in aggravation reduction) but I need more active WiFi control in this network-dense environment.

As noted in the comments, the jailbreak app SBSettings covers a lot of these use cases; if you're in a WiFi hot zone and you can't take any more, it might be the tool that pushes you to jailbreak your phone.

GotThis?: One of the favored activities of appoholics, when meeting in their secret underground lairs, is comparing screenfuls of cool iPhone apps to see what they might want to download next. It would be easier if these phone-waving sessions could be automated with -- of course -- an app that would compare your installed suite with that of your neighbor's, point out what he's got that you don't and vice versa, show you most-run statistics and then perhaps link you to the App Store if you've gotta have one of those apps right away.

The problem is that the roster of installed apps is not accessible to a sandboxed app running on the phone, at least not under SDK rules; one way to do this would be to scrape the installed app profile from iTunes and then store it, with the user's permission, on an external website (leveraging the existing iUseThis for iPhone, perhaps). Give this app the interface and location awareness of contact sharer & billionth-app Bump, let users tap iPhones to compare installation profiles, and you'd have a fun social networking tool plus an appoholic enabler of devastating proportions.

What's on your app wishlist? Have you seen apps like these, either in the App Store or in the Cydia Store? Let us know below.

If you're a developer running the iPhone 3.0 beta, you may have gotten a special note in your email today -- and judging by the number of you who let us know about the news, there's plenty of those emails going around. Apple is testing the long-awaited push notification feature of the 3.0 software (and the back-end servers that provide the updates) with a build of the Associated Press news update app. If you got an email with a promo code and you've been putting the app through its paces, do let us know how it's going.

Push notification is all well and good, but what about true background processing for those critical applications that need always-on connectivity? More on the prospects for that capability in our next post, coming up shortly.

Thanks to everyone who sent this in.

[H/T to Engadget]

The Wall Street Journal's Digits blog takes a look at "crap apps" -- those pieces of junk on the App Store that do one thing and do it pointlessly, whether that thing be farting or belching or making the sound of fingernails on a chalkboard (yes, really) or what have you. And they come up with a very intriguing, albeit obvious, reason that the App Store seems so filled with completely terrible and silly apps. Why? Because they sell.

Yes, even "legitimate" iPhone developers -- those people working hard to create an innovative touchscreen interface, or bring some crucial functionality to the iPhone -- are finding that of all the apps they release, the crudest and most stupid are the ones that sell. They profile a guy whose serious movie apps aren't selling, but whose cobbled-together-in-five-minutes gimmick apps are making a mint. In short, the reason our App Store is full of way more fart apps than apps like Twitterific 2.0 is because people are paying for the fart ones. The message we're sending with our wallets is that if you want to make a million dollars on the App Store, don't toil away to polish your groundbreaking award-winning puzzle game. Just give us a gag we can show to our friends.

Is it right? I'd say no, but then again, even I have been pulled in to a gimmick app or two: I bought Cat Piano (in my defense, I've gotten enough entertainment out of it to find an easter egg: shake your iPhone while playing). But next time your finger is poised over the "Get App" button on that 99-cent belching app that you just know the friend you're seeing later will get a total kick out of, think to yourself: is that two-second gag worth an App Store full of crappy apps?

iPhone OS 3.0 beta 5 was only released for general consumption yesterday, and already Apple is rocking our collective faces off with big news. While a cool new feature being uncovered would be great, what Apple has in store for would-be iPhone application submitters is a bit more challenging.

Effective today, Apple will no longer be accepting any iPhone or iPod touch applications that are not compatible with iPhone OS 3.0. According to an email sent to developers,

"Beginning today, all submissions to the App Store will be reviewed on the latest beta of iPhone OS 3.0. If your app submission is not compatible with iPhone OS 3.0, it will not be approved."

While this may make sense at first glance, consider that OS 3.0 does not yet have a release date and developers might be pushed to spend time and energy tweaking apps against an unstable OS base. Also, any devs who only ship free apps will now have to pony up $99 to join the beta if they want to debug their apps against the new version.

Further, it seems that Apple might be removing existing applications from the App Store, once iPhone OS 3.0 is released, if it is found that they are not compatible with the new operating system. So grab your Twitter clients and flame-throwers, it's gripin' time!

Update: iPhone Developer Program enrollment is required for App Store application distribution; regardless of whether the application is free or paid, the enrollment fee applies, and any developers with apps in the store have already paid their $99 for access to the beta. Thanks goes to our intrepid commenters for reminding us.

Thanks to everyone who sent this in.

[via @razorianfly & the Loop Blog]

Version version, who's got the new version? iPhone OS 3.0 beta 5 is now downloadable, along with a new build of iTunes 8.2 -- log into developer.apple.com to pick up the latest build.

What's tweaked and changed? Well, editing the carrier file in iTunes to enable tethering is now apparently blocked, and MMS support on AT&T is also 'hidden' per the iPhone Blog. It's not 100% clear whether these feature drops are deliberate, as some reports say a clean install preserves the capabilities. Parental control features for apps now seem to be visible... and yes, the new beta has already been jailbroken.

Got more observations and tidbits? Let us know below.

Thanks to everyone who sent this in.

iPhone developer Emanuele Vulcano pinged us with a note today telling us about a free file transfer app for the iPhone. Since most file transfer apps are a real yawner, I was dubious...until I watched the video.

What makes Mover (click opens iTunes) so cool is the way that it does the transfer. When you want to transfer an image or a contact card to another iPhone, you just launch the app on both devices, grab the image or card, point an arrow on one screen to match up with an arrow on another iPhone screen, then flick an icon representing the data you're sending. It moves off of your screen, and onto the other iPhone's screen, and the data is saved automatically. Very cool, and very iPhone-like!

Both iPhones need to be on the same WiFi network; there's no current way to do this over Bluetooth or a cellular network connection. Emanuele has made his code open source under the BSD license, so other developers are welcome to take a look at how he did this.

Check out Mover here (now with the correct embedding info):