At the moment I'm playing a bit with my pinetime smartwatch(es) and want to try wasp-os (python based development). I could flash the bootloader as described in the documentation but was not able to flash micropython.zip via the nRF-Android-App, so I tried to use the linux based approach. Problem, gatttool was not part of blueZ-library anymore. In order for this to compile you need to add following package:

bluez-utils-compat

After that you gatttool and hcitool should be installed.