I have had the app on my ipod touch for a couple of years now. I don't use it very much as I have an android phone but I used to use it pretty regularly. It is just like the photograde website but its just an app for the iphone/ipod touch. If you have used the photograde website the app looks exactly the same, the only difference is you do not have to have internet access to use the app (at least you didn't have to, not sure about now)