This very little application switches Bluetooth ON when phone is connected to the charger.
When disconnected, it switches Bluetooth OFF after a time, to prevent Bluetooth to be switched off during the ignition of your car for example.
New on the paid version:
You can now manage Bluetooth, WIFI and mobile data (not on Lollipop).
You can add some delay before activating. This improves compatibility with some bluetooth devices.
Some minor bugs fixed.