If you like to tinker with Sony Xperia devices, things just got a little more fun (funner, if you will). Thanks to Sony's newly-released Illumination API, developers can now tweak the illumination bar settings on compatible devices, including the Xperia SP, ZL, ZR, UL, A U, L, S, SL, P, sola, ion, acro HD, go, M, and M dual.
Sony is calling the Illumination API an experimental API (the first of its kind for the company), which essentially means it will be released with limited documentation and virtually no support; basically, you're on your own with this one. Fortunately, it seems pretty straightforward – it can be used to control the LED color, the pulsation and time between pulses, as well as pre-defined fading patterns on certain models. The API also allows the LED to illuminate in rhythm with music on the Xperia SP. Neat stuff.
A full list of supported phones, along with how to get started with this new API can be found on Sony's developer blog – head there for all the details.