Most of those successful photography apps use the same method of altering an image by applying layers upon layers of textures or filters onto original image from Photo album. Some designers got it right some not. Mextures is very good. The tool set is very good and it is working right. Layer blending modes are there which is very important. It lacks set of more original presets and ability to work in both portret positions. Many apps fail there. Sometimes I work for hours on my iPad and the power cable is plugged in. That prevents iPad of being comfortable set in the lap because the cable plug gets in the way. The solution is to simply turn iPad for 180 degrees but the app does not allow that. Also it would be good to be able to reapply original image or any other image at any point and then blend those layers.
Mextures is very good app and it is highly recommended for lovers of iPhone photography. It does bring improved workflow with its Formula tool and it is very stable. And the price is right.
Staklena Voda about Mextures Photo Editor, v2.0.0