I use the NewPipe fork with Sponsorblock as an optional feature. You can get NewPipe on F-Droid here and the fork with Sponsorblock here.
As a rule of thumb, I always check their respective GitHub pages for links, I don't really trust the Google Store. There are too many spam duplicates of various apps, especially FOSS ones.
Reader mode is one of the reasons why I keep going back to Firefox or Firefox forks :). I really love how it just works, and how it also can unlock semi-paywalled (soft-locked) articles.