Ok, so where is the problem with my test app that @Taifun mentioned in post #9 ?
Anything, the app that don´t work is the one that CrisWard send in post # 14
.... you did not see any error messages from the code I sent you?
How did you run it? As an APK?
No, i didn't see any error in the code, the Bluetoothlist just kept blank and thats it
I've run it as an .apk in my phone
(I am a beginer, i don't really know what errors i need to look for, sorry)
Curious. I had only 3 devices in range here but they were all found and listed. I added error code blocks, if an error occurs it is reported in a Label "Label_Message" at the top of the screen. I also automated requesting Bluetooth be switched on (on your phone). So many others have been successful I was sure it would work for you too 
However, if Anke's code works we should see where the problem is.
The app has ubication and near devices permission granted and doesn't shows any error label (i have tried it in two differents phones)
Which problem? Show your (relevant) blocks.
You get a list of Bluetooth devices, which looks fine... What exactly are you expecting?
Taifun