Android/iOS: When it comes to mobile photo-editing applications, few offer advanced functions. Handy Photo doesn't hold back, adding powerful tools such as a clone stamp, perspective correction and selective editing features.
The app includes built-in tutorials for a number of different tasks. You can remove people and objects from photos, select a person and move them to another spot, or apply selective filters. While it's no replacement for a desktop version of Photoshop, at $2, it's at least worth considering over the considerably more expensive Photoshop Touch.