iOS has a big collection of photo editors, but HelloLab stands out with its elegant, iOS 7-ready UI and unique take on making quick edits.
Sliders are used in almost every photo editor to apply effects and filters. Usually this is a good thing, but I sometimes find myself spending way too much time trying to move my finger a millimeter left or right to get things just right.
This app have almost the same thing which you all would except from it, but it just gives you only five options on each slider to choose from. For example, the temperature slider has settings that could be described as very cool, cool, neutral, warm, and very warm. You may experience a little less output, but hopefully be able to make your edit a little faster. I may be a good choice for making a quick touch-ups on your pics before sending it through mail.
The app is free, but offers extra filters for $.99 each, so you should definitely give it a look.