The «Апологетика: неоязычество» (“Apologetika: Neoyazichestvo”) app has been long-forgotten and was made unavailable on some stores, due to the lack of updates.
Those updates are now back in place, and the app is once again available for download, for free, on the respective app stores for iOS and Android:
https://play.google.com/store/apps/details?id=eir.neoyaz
https://apps.apple.com/us/app/апологетика-неоязычество/id1038143218