Since the game was released in 2017 it unfortunately means that on rare occasions (typically once a year) the companion app isn't compatible anymore with Apple or Google's rules for their stores. We do still actively update the companion app to avoid this situation, especially since it means the app can disappear from the store, but unfortunately it occasionally causes the issue that the app just isn't available for download anymore. We deeply apologise for this inconvenience and appreciate that it's very frustrating.
When this happens we recommend that you check our Discord for updates. In most cases the companion app will be back for download in a few days, we typically recommend checking our Discord and waiting until it's back.
Temporary Workaround for Android phones (proceed at your own risk):
If you own an Android phone and are relatively technically savvy then we do have a temporary workaround. Please note that we can't provide any support on this workaround, especially not on anything related to your phone, and that if you decide to proceed it means that you're doing this at your own risk.
You can download the APK file for the companion app here. Please note that this is the only place we offer this file for download, and you shouldn't download it from any other sources (unless it's from the Apple App Store or Google Play Store of course). For technical users: the CRC-32 for the APK is E2DB8929. Now install the APK onto your Android phone.
Unfortunately there is no temporary workaround for iPhones.