NewPipe

NewPipe is a great app for watching YouTube videos on Android devices without ads or data collection. It has many useful features that make it convenient and functional. With NewPipe you can:

1. Watch videos in the background so you can continue listening to audio even when you exit the app or lock the screen.
   Download videos to your device to watch them later without an internet connection. You can choose the resolution, format and download speed.
2. Use the pop-up player to move videos around the screen and watch them on top of other applications. You can change the size and position of the player as you wish.
3. Subscribe to channels and create playlists to organize your favorite videos. You can import your subscriptions from YouTube or add them manually.
4. Support different languages and regions, and customize the quality of the stream. You can select the language of the interface, content and subtitles, as well as the region that determines the availability of the video.
5. Don't use Google's proprietary APIs and send the minimum information necessary to do your job. This means you can watch videos without registration, advertising, or tracking your activity.

Overall, NewPipe is a great alternative to the official YouTube app for those who want to avoid ads and respect their privacy. It has all the basic features you need to watch videos and gives the user more control over their experience. It's also free and open source, meaning it's made by the community for the community. It is an ideal choice for anyone who loves to watch YouTube videos on their Android device.