During my search for math apps, I found several by Varsity Tutors and they have so many. I found each app has a flash card maker, practice test, diagnostic test, learn by concept, flashcards by concept and a question of the day. Very complete coverage, with excellent examples and explanations.
I love that they have so many apps for High School Math. They have:
1. High School Math
2. Algebra II,
They cover every class I am teaching and each app can support most or all the the math I need the additional support in. Yeah. Tomorrow I"ll look specifically at the Trig one to give you an idea of what the apps in general offer.
The best think of all is that the apps are free and you do not have to purchase upgrades to access all the materials. I am going to have all of these math apps downloaded so I can use them in all my classes.