Bluetooth keyboard -> Needs no root

[bessw]

I recently found a Android app that works as Bluetooth mouse and keyboard without root (and without a server app on the pc!)

This would be a really nice alternative to rooting the device or buying some special usb-stick, since many laptops have Bluetooth builtin and for others a bluetooth-stick would be cheaper.

[MzrW]

I came across the same issue and invested some time, have a look:
https://github.com/MzrW/K2ABluetoothKeyboard