The developer got kicked out of the Play Store for bogus reasons, and had to continue to develop it as an externally funded effort. Support him, buy a pay what you want license, and give him a couple bucks for it if you value open source software like this.
(I'm not affiliated with the project, I just love the app and it runs on all my degoogled devices)
Additionally, degoogle your phone by installing an open source ROM like GrapheneOS [4] or LineageOS [5], and install only the most essential apps on your phone.
There's also App Warden [6] which audits installed apps, by scanning them for malicious libraries and adtrackers. It's based on the dataset provided by Exodus Privacy [7] where you can search for Apps or their APK identifiers and find out what kind of fingerprinting libraries they're using. For example, this is what the Facebook App uses behind the scenes [8].
Don't install gapps and neither the google play services. If you want an app store for the convenience of updates of open source apps, there's also f-droid [9], a libre app store for Android.
Additionally you should keep in mind that every app that needs google play services to run is spyware, by definition of what these services offer as APIs. Websites that require you to install their app to "verify" you are usually spying on your activity.
[1] https://openwrt.org/toh/start
[2] https://openwrt.org/docs/guide-user/services/dns/adguard-hom...
[5] https://wiki.lineageos.org/devices/
[6] https://gitlab.com/AuroraOSS/AppWarden
[7] https://reports.exodus-privacy.eu.org/en/
[8] https://reports.exodus-privacy.eu.org/en/reports/com.faceboo...