SL Soundboard is a free Android app developed by TrailerParkBoy in the Multimedia category, specifically for music and radio. The app lets you play the announcements from the Stockholm subway as ringtones and notification sounds.

With SL Soundboard, you can relive your daily commute or add a unique touch to your phone's sound alerts. The app features a simple user interface and all the subway announcements are listed alphabetically for easy access. You can also search for a specific announcement by using the search bar.

Overall, SL Soundboard is a fun and quirky app that offers a unique way to personalize your phone's sound alerts with the familiar sounds of the Stockholm subway. It's a great choice for those who want to add a touch of local flavor to their phone.