I actually run a site that does something pretty similar [0]. The major difference is that I "group" verbs into sets with identical conjugations.
I then use spaced repetition to generate the "flashcards", but substitute grouped verbs at random. The idea is for you to get a feel for a conjugation so that when you see a new verb in the future you should have a good sense of how it conjugates. (as a trivial example, if you know how to conjugate tener, you should know how to conjugation detener).
I built it for myself years ago to quickly master all the verb conjugations for all tenses (it takes about 4-6 months), then cleaned it up for others.
I also give a multiple choice option, since on mobile its not always convenient to type.