That's how it works:
Pair your Laser Distance Measurement Device (Leica, Hilti, Würth, Laserliner, Bosch GLM 50C) with your phone.
Give in a name for your project (e.g. customer name)
Give in a name for the window (e.g. kitchen, living room left)
Connect your Laser Distance Measurement device over Bluetooth
Make a measurement, check it, send it to the app with the Bluetooth button.
You can follow a predefined measurement sequence