background remover

what apps do you guys use to remove the background off a picture and make it a sprite? I could use photoshop touch for the iPad but don’t feel like spending another 10 bucks. any good apps you’ve tried?

I prefer to do intense image editing like this on my pc and not my iPad; a mouse seems better suited to the task than a finger for fine editing, and there are plenty of free tools. If you must edit on the iPad I suggest ponying up and buying photoshop, as it has transparency, can save as png, and works pretty well.