Here are some projects i never got around to, if you're interested.
Youtube Collections - youtube used to have "collections" where you group multiple subscriptions in them, and filter on just those collections. for example, some of the Collections i used were Chess, Music, and Cooking. youtube took that away, so now i gotta dig through my subscriptions to see chess videos. Project is to implement your own collections. you can create a desktop app, android app, ios app, browser extension, separate web page, or whatever you prefer.
Netflix - i havent used netflix in a while, so things may have changed. their video recommendations / wishlist implementation was complete shit. Why on earth would i want to see videos i've already watched/rated/wishlisted in the movie recommendations list? there's also no way to black-list movies/actors/directors i'm not interested in, so i see the same terrible recommendation again and again. you can create a desktop app, android app, ios app, browser extension, separate web page, or whatever you prefer.
Music Recommendations - i dislike almost all male vocals. but there isn't a single music discovery app that lets me filter to exclude male vocals. I don't use many music apps, so you can decide the best way to handle it.