This app uses your Android phone’s LEDs to create a light show for your music
negated the need for built-in LEDs. After all, what more can a blinking light tell you than a screen? Luckily, crafty developers are finding other uses for the neglected multicolored diodes. One app for Android, LED Music Effects, turns your device’s LEDs into a basic music visualizer. The app, which requires root access to work, reflects the rhythmic punctuation of songs on your smartphone’s built-in LEDs. As the app is currently configured, a single LED alternates between three colors (up to three work synchronously).