Lo-Fi Room - video preview
Lo-Fi Room won Pocket Gamer's most recent Big Indie Pitch at G-Star. Developed by one person, it's a chill music rhythm game by way of a hidden object puzzler. You explore rooms, locate instruments, then play them to build songs.
In addition to the story campaign, there's also a free-play room where you can just lay down tracks and jam at your leisure. The first 3 levels are currently playable in beta on PC and browser, and the full game will be out on mobile early next year.