Thanks for your comment! I wasn't aware this was the case and will check it out immediately. The codebase is quite old at this point so it might be difficult but I will give it a shot!
Happy to help if I can! While I work on deploying a version targeting newer Android releases, I managed to activate a setting with Google Play that should allow the app as-is to continue to be downloaded. Would you mind trying again? I'm also running Android 13 and as I had the app already downloaded, I can confirm it works the same.