If you like newpipe checkout tubular, it's a fork that adds some improvements.

Qr scanner. I like that it saves a history of scanned QRs and shows you a warning that scanning qrs can be dangerous

Money wallet, to keep track of expenses

Joplin, for note taking

Addy.io, for anonymous emails aliases

Shelter, let's you create a work profile to keep things separated on your phone

Thunderbird, email reading

Seeneva, to read comics