The highly-rated and popular drawing app for the iPhone and iPod touch, Sketches, has been on sale through Christmas. Now LateNiteSoft has extended the sale through December 31 to give more people the opportunity to draw on their pocket devices.

Sketches (click for TUAW review) is not only fun to let the kids play with, but it's great for creating quick drawings and annotating iPhone pictures. It comes with a bunch of pre-created shapes, you can use photos or a map of your current location for a background, and there's even an eraser available. It's the most drawing fun you can have without a Newton MessagePad (by the way, my MP2100 will be accompanying me to Macworld Expo again next week).

Sketches has been a favorite in the App Store (click opens iTunes) since July, and it's now in version 1.4. The App normally sells for US$4.99 / €3.99 in the App Store, but during the sale it is discounted 60% to the low price of US$1.99 / €1.59.

Jorge Llubía, co-founder of LateNiteSoft, has stated that there will be a 1.5 release, and then Sketches 2.0 will be released with major new features. Both of the upgrades will be free to registered users.