Bluetothverbindung breaks permanently from

The charger isteigentlich not bad, but because the main difference, the Bluetooth function does not work properly (but could also be due to the APP - which is not maintained) can I forgive maximum 2Stars.

The problem is when I start the device and connect to the tablet / mobile funktioiert everything, even the einstelmöglichkeiten are good. However, the connection breaks regularly provide from (what the sign of the charge curve makes impossible), sometimes the Tab / mobile can establish the connection again, sometimes the charger needs to be completely cut off from electricity. What during a loading operation is of course nonsense.