The parameters (or extras) will be printed to a connected bluetooth printer
as pairs key : value
The app should verify that the printer is available. and issue error messages if necessary.
beside this it should work unvisible
Calling the app 'stand alone' will open a screen which allows to enter 3 parameters
and save them to a file. It will also allow to test the availability of the printer.
The parameters will be read from the parameter file when the app starts.
Use Kotlin - Should work o 4.4 +.