I’ve only been using this app two days, but this app has taught me so much already!
It would be nice if it let you pause at your current level, so you could keep practicing what you’ve seen so far without introducing new hiragana, but it progresses at a fairly manageable pace. Another feature that I’d appreciate would be the ability to practice a specific consonant or vowel’s hiragana!
Without these features, though, it’s an extremely responsive and effective app. I recommend it.