Fat Bits is a fun, cleverly-made app that allows you to create and edit icons pixel by pixel with great effect. The resulting images and icons you create are unique in a number of ways, but most importantly, you can make them with a few basic taps of the screen. There are no pallets or overly-complicated tools needed. Just tap and drag and pixels change colors at your whim.
The interface for FatBits is where it really shines the most. Onscreen is a selection of icons to choose from, a canvas on which to edit what you've selected, and a number of previews above to see what it will look like when saved and exported for use online. While the icons are designed for browser use, there are a number of places they could be used and the export feature works quite well. You can even tweet the icon directly from the app if you want to share it with friends and followers.
While there is a paid upgrade that allows you to change things like hue, saturation, and brightness, the free version of FatBits is a lot of fun to play with and surprisingly feature rich. If you need to create an icon, or would like to play with what FatBits has to offer, check this app out. It's free to download, easy to use, and loaded with a number of fun options to explore how your icons can look.