I really wish I could say this was a great app, but it would need a lot of work to get there. With the developer site no longer available and no recent updates, I doubt it will get the attention it needs to be a great app.
The idea is solid. It's much like Duolingo, which doesn't currently support Arabic. Certainly this app has a lot of marketability for Arabic learners. However, the app is buggy to the point of being broken.
In the alphabet learning section, typing in the correct Arabic letter with diacritics (and without) results in a missed question. When your "wrong" answer is identical to the "corrected" answer displayed under it, that is a huge bug. After 4 typed-in questions, you automatically fail since you can never answer those questions correctly.
This seems to be the case with all of the typed-in questions in the entire app, which makes the first lesson impossible to complete. This would be discouraging to any new learner.
Developer, wherever you are, please update this app!