Greek and Latin apps for iOS are often somewhat disappointing. "Liberation Philology" apps don't promise much, but they certainly deliver. They actually make several apps for a number of languages, all based on the same engine. Even Old Norse can now be studied on an iPad. For our purposes, Latin and Greek are sufficient. The design of the apps is very simple. You can choose to study Vocabulary, Nouns or Verbs. There are also paradigms that you can review. The app has a nice flow to it (I tested the Greek version). You don't have to make too many selections while using it. I did not see any errors, although at first I missed the fact that there are two types of questions for verb parsing. Sometimes you have to identify a form and sometimes you are asked to pick the form that corresponds to a specific morphological description.
I do wish it was possible to fine tune the lists of words. Way too often I end up seeing words that I have known for decades (for me, this is particulary true when I use the German version of this vocab app).
Liberation philology apps easily get lost when you simply search the AppStore for Latin or Greek. So, if this is something that you might be interested in, check them out. They are not free, but still not expensive ($2.99).