josheron

For me would be on Android:

Seal: for downloading any video, specialty YouTube

ViMusic: For listening to music from YouTube

Paisa: for budget control

Read You: best RSS I had seen on Android

Xtra: Twitch client without the ads

Quacker: For following Twitter accounts without creating and actual account or interacting with them t all.

Most of them are on F-Droid and they use material design.

Let me know if you want direct links. And Droid-ify is the best F-Droid store client out there