Piano-Simple Vertical is a free Android app developed by 株式会社GENIT. As the name suggests, it is a simple piano app with a vertical orientation that makes it easier to use on your phone. The app provides six different instruments, including piano (bright), piano (warm), electric piano, harpsichord, acoustic guitar, and electric guitar.

One of the best features of Piano-Simple Vertical is its flexibility. You can customize the number of tiers from 3 to 5 for easy use. Additionally, you can change the number of steps to fit your preferences. The app is perfect for beginners who want to learn piano or people who want to practice playing their favorite tunes on the go.

Overall, Piano-Simple Vertical is a great app for anyone who wants to play piano on their phone. It is simple, easy to use, and provides a great sound experience. If you're looking for a no-frills piano app, this is definitely worth checking out.