The Textiluhr Manager is only compatible with the Textiluhr TX15 and future versions.
The Textiluhr nach Kretschmer (until 2014 produced by the HSL GmbH in Heidelberg) is an air-permeability tester and can now be purchased from F.O.S. Filtertechnik GmbH via textiluhr.de. Even though the website is only available in German yet, we can provide all required information in English.
Even though your device is marked as compatible by the google play store, it is mandatory that it supports media control buttons from headsets. You can find a list of compatible devices on textiluhr.de/shop/kompatible-android-geraete/.
You can test the Textiluhr Manager by using a media control headset or the volume buttons of your phone to create some dummy measurements.