Tune Ai shows which harmonica holes you are playing and how much you are bending.

Play single notes better: See if you are playing multiple holes by mistake.

Play chords better: See if you are actually playing all 3 holes or only playing 2 holes or playing the wrong set of holes.

Practice bends and bend in tune - Shows how much you are bending and how much more you need to bend to get to the next note. Or if you are bending too much.

When practicing songs and riffs see if you are moving to the correct holes or not. Without having to stop playing.

Can't find harmonica tabs for your favorite song online? Just play the song on YouTube at slow speed and watch in app which notes holes or chords are being played.