Good Gear Guide
In pictures: 15 must-have iOS apps you can't get o...
Mextures (iPhone, iPad and iPod touch)
Mextures is just one of many iOS-exclusive photo editing applications that deserve a home on your iDevice. The app lets you apply "textures" to your images and then add "layers" for custom creations. The true value of the app is in fiddling with the textures and layers to find combinations you love, which you can then save as "Formulas" for use on other images. The app makes other users' popular Formulas available as well. Mextures is also a must for avid Instagramers.
In pictures: 15 must-have iOS apps you can't get on any other platform