Because, at the moment, I'm not able to use the emulator in Windows due to a problem in Wine: so I have tried to use the emulator in my Linux distro (Ubuntu), which requires the app to be installed by adb as B4A runs under Windows (i.e. for me, in Wine).
I can test it in a real device but it's a slightly convoluted procedure to transfer & install in a real device as I can't make B4A compile to a real device: probably due to another problem in Wine.