I have been plagued by this thing for a few weeks: every time I turn on the Wi-Fi, then turn it off, something starts turning the Bluetooth on. Turn it off and it goes back up in a minute. The only solution was to turn off the phone and then back again without turning Wi-fi or Bluetooth on. Strangely enough, there is no way to disable Bluetooth on the phone and no way to know who turned it on last.

As an investigation, I tried something called Event Logger, which logs when Bluetooth is turned on or off, but fails to notify you of what did it. In fact, I am still not sure how I was supposed to determine what software did it and this demonstrates a systemic issue with mobile phones: you have no real control or even knowledge over what happens in it.

Long story short, I've uninstalled a lot of applications just to see if the problem goes away. In the end it was Firechat! After uninstalling it, the problem went away. Apparently I am not the only one experiencing this, although one of the few pages on the Internet regarding Firechat and Bluetooth claims Firechat does not turn it on by itself, although numerous reviews on the app's Google Store page say differently.