I've always thought the illumination strip located at the bottom of some Sony Xperia devices to be pretty funky. Despite how 'gimmicky' it feels, the novelty is sure quite fun. This is evident with its ability to light up with the color that's most prevalent in an image in the gallery app or the album art in the Walkman app, as well serving as a notification light for messages and calls. In fact, users loved it so much that Sony even decided to release the APIs behind them, as to allow further developmental work to leverage the illumination strip.

With this in mind, XDA Forum Member sagar29 decided that the Xperia SP can even serve as a disco light, so he developed the aptly titled application Discolight. The app allows you to control each of the three LEDs of the illumination bar with individual RGB color selectors. It also gives you the option to randomize the pulse color and to start the app on device boot.

With Discolight activated, any audio output will be accompanied by your personalized light pulses, including music and phone calls. Apart from requiring root access, there really isn't much else needed. Just plug n' play and you're good to go.

If you'd like to check this app out, visit the forum thread for more information and download.