If you can’t install Strategway Passim from Google Play (e.g., it was archived there due to inactivity), then you can always download an APK binary package on your phone and then install it.
This is the latest version of Passim: passim-0.8.18.apk.
This video explains how to install an APK file after you have downloaded it to your phone:
After installation is complete, please proceed to the user manual to set up the application and start using it.