SketchBook Mobile recently got a mention here as the best iPad app fro sketches, notes, photos and more - and now its available on Android. I bet if you have a Samsung Galaxy Tab - this should be the first app that really is worth paying for.
With so many features - it can be hard to know where to start - so my suggestion is use it to play around with some of your photos. Or if you are into design or UE / UX then open up a recent screenshot and play around with adding layers and notes.
Tags:Read more from my blog for an introduction and quick tips on developing in Hugo or UCTD.