Based on the users' reviews of the FNF Piano app, here are three cons and pros in 15 words or less: **Cons:** 1. Many users find the app's tutorials unintuitive and frustrating. 2. Some users report encountering annoying ads and pop-ups frequently. 3. Others complain that the app can be slow and unresponsive at times. **Pros:** 1. Users praise the app's accurate piano simulation and realistic sound. 2. Many appreciate the vast song library and option to create custom playlists. 3. Reviewers find the app's user-friendly interface and navigability a major plus.