With this free app for Android, you can simulate a blacklight with the screen of your smartphone or tablet. The produced light is close to the ultraviolet color spectrum and looks deceptively real, but as pure simulation without real UV rays.
Use the blacklight lamp as a general optical accent or to prank your friends. They do not know that it is app just generate a violet colored screen and the will think you could produce true black light with your smartphone.

To turn on the animated UV tubes, it requires a simple click on the screen. Similar to a real lamp, you can hear the shift acoustically. Consequently, in order to switch off the black light again, just click one time more on an empty part of the free Android app.

If you like this application, then please rate it positive at the Google Play Store. However, always keep in mind that this is explicit marked as simulation for the pure entertainment, becaus a smartphone or tablet can't technically produce a real blacklight with their ordinary screen!
If you find a bug, or if you have a feature request, please send me an email. I will reply as soon as possible in German or English.