People interested in piracy are also interested in ad blocking. Seems relevant to me.

Why not change your system DNS to the public AdGuard address? Then you don't need to use the app. DNS filtering is still more limited than uBlock, of course, but if you refuse to use browsers where that's available, I think that's the next best option.

Use Jackett to search many free trackers at once. BTDig is also good, but as just a simple DHT search engine, it won't tell you the health of the torrent.

Moon+ Reader is great if you want a library in your phone. It's very customizable, too. But it's not great with PDFs, and few third-party apps are. If you're reading on a phone-sized screen, the official Adobe Acrobat app is the best for text reflow on PDF files. It maintains a lot of the formatting making it very comfortable to read. Unfortunately, nothing else about the app is that great and it won't give you a good library view like you're asking for.

Similarly, ReelGood is another real good option. But there are many sites where you can track what you watch and get suggestions on what to watch next.

Tencent also put the whole thing on YouTube for free with English subs. But of course YouTube audio maxes out at 128kbps stereo.

Remember that story about Gen Z students not understanding file systems?

Time shifting is legal.