Netflix, Prime, whatever - before I watch pretty much anything I'll look up the IMDB and Rotten Tomatoes (critics & users - I'm happy to watch something with a low critic score and high audience score, it's probably super enjoyable trash) scores. Generally below a certain threshold I'll skip it unless I'm desperate.
Honestly, I wouldn't use an app. It seems like you're solving an already solved problem. I can type pretty much any film/show into Google and it'll give me all the cast, links at the top to RT and IMDB, along with a score for each etc etc. There's literally bar at the bottom of my phone screen to type into, with a microphone if I don't want to type.