There’s so many I could list, I’ll just mention 2 underrated ones I don’t see mentioned as much:
LibreTube - Best YouTube client imo, has a very nice and modern interface, proxies videos through Piped for maximum privacy (No direct connections to Google are made), No ads/tracking, SponsorBlock + Return YouTube Dislikes, support for downloading videos, etc. It’s everything I’d want and more out of a YouTube client.
URLCheck - Excellent app that allows you to preview what a URL is before you click it, includes tons of features such as scanning for malware, removing any tracking parameters, upgrading links from HTTP to HTTPS, etc. I can’t recommend this app enough for the security, privacy, and general peace of mind it gives you.