Best image-editing app for Android

PhotoDirector is the whole package. It has everything you could possibly need to edit your photos. The tools range from simple text bubbles and filters, to more complex things such as HSL and curves, and they're all heavily adjustable, helping you get the best out of your photos. It's for messing around on and seeing what you end up with.

The app is developed by CyberLink, a large Taiwanese multimedia software company, so they have the money to splash on an app, and it shows. Highly recommended for novices and pros-on-the-go alike.