Amazon Music★★★☆☆I want to use it to listen to music. Amazon wants to use it to sell me more subscriptions.
iNaturalist (App)★★★★★Streamlines the basic use case of posting an observation from your phone and narrowing down the plant or animal you're looking at.
KeePass Password Managers★★★★★KeePassXC, its browser extension, and KeePass2Android are a nice, clean set of apps to manage your passwords on your OWN desktop and mobile devices, auto-fill websites and apps, and sync over your own server or cloud provider.
KeePass2Android★★★★★Nice, clean interface to a KeePass2 database with auto-fill support for both websites and apps and seamless syncing over your own server or the cloud of your choice.
StreetComplete★★★★★StreetComplete is an easy way to contribute to OpenStreetMap on the go, as a beginner, or both from your Android phone.
Tusky for Mastodon★★★★★Impressed at how smoothly the app works, especially with multiple accounts.
Vespucci (App)★★★★☆Vespucci is a powerful editor for OpenStreetMap on Android that can handle just about anything, though the learning curve is steep.