PDF Cabinet is one of many PDF tools on the App Store, but Cabinet features some niceties like real-time collaboration and drag-and-drop document management. It also sports a skeumorphic or "real-world" look, complete with stitched leather, if you're into that sort of thing.

In the video below, we talk to Andrey Podshibyakin, one of the creators of PDF Cabinet, about how it came to be.