I've tried probably 15 piano apps at this point. Some are genuinely helpful. Most are not worth your time. Here's my honest breakdown.
Learning apps (Flowkey, Simply Piano, Yousician): These connect to your keyboard and give real-time feedback. They're polished, gamified, and fun at first. But here's the problem: they don't teach you to read music. You're following lights and colors, not learning notation. When I stopped using the app I realized I hadn't internalized anything. This connects to what I wrote about YouTube tutorials creating dependency.
That said, they're great for initial motivation. If an app gets you excited to practice, use it – just don't rely on it exclusively. Supplement with actual music reading from day one.
Theory apps (MusicTheory.net, Tenuto): Excellent for drilling fundamentals. Note identification, interval recognition, chord building. MusicTheory.net is free and comprehensive. Use these actively – they fill gaps that playing alone doesn't cover.
Metronome apps: You need one. Pro Metronome or any basic free one. Essential for developing timing.
Sheet music apps (MuseScore, ForScore): MuseScore has massive library of user-uploaded arrangements. ForScore organizes your sheet music library on tablet. Both useful if you're reading from a screen.
Moises lets you slow down songs without changing pitch. Super useful for learning songs by ear. Free tier with limits, paid version for more.
What I actually use: MusicTheory.net for theory drills. Metronome app. MuseScore for finding arrangements. Moises occasionally for slowing songs. That's it.
What I stopped using: Flowkey after month 3. Fun but wasn't building transferable skills. Any app that felt like playing a game rather than learning music.
The meta-point: Apps are tools, not teachers. They supplement practice, not replace it. Time with apps should be maybe 20% of practice time. The other 80% is actual playing with a structured practice routine.