Saw an ad for this on the creativeapplications.net site (followed links in the upcoming eBoy game FixPix article) and thought it looked pretty interesting. There are a few videos on the site sktchapp.com App info is currently processing and/or the app is not yet fully available for sale on the US App Store.
Pretty neat application, there are a good amount of presets included. Combine this with sketchbook or another drawing app and the possibilities are endless. You can import pictures as the background in SKTCH, and then draw abstract patterns on it. My only gripes are that the app can lag a lot since presets are changed in real time. I also noticed it drained a hefty chunk of my battery. Other than that it's awesome.
I use an all black background, change the presets to my liking, and then screenshot my work (no "direct" way to save an image to photo roll besides this) and open it in sketchbook. Then I edit it a little and email myself a .psd that I can use in my photoshop projects.
Hi all, glad you are enjoying SKTCH. We just submitted an update which includes "Send to Desktop" feature allowing you to send your drawings to the desktop version of the app which is currently in the works (preview). Also SKTCH Remote iPhone app is coming..allowing you to draw using your iPhone (see this tweet). If there is anything you'd like to see in future version, please let us know. Filip