A free app for Android, by Army Music.

Army Piano: BTS Music & Piano! is a piano game with a unique style. The gameplay is very easy to learn but can be very challenging to master. The aim of the game is to tap the tiles as they appear on the screen. Each time you tap a tile, it will fade out and then appear again later. You need to be very quick and accurate in order to succeed.

There are many different songs in the game, all of them are very popular and are played in every corner of the world.