One of the features that would be very valuable for hardcore movie lovers is the ability the view and sort / filter by 3rd party ratings, such as:
1) Letterboxd - this has an official API: http://api-docs.letterboxd.com/
2) Metacritic - no official API listed, but they likely have some commercial version
3) RottenTomatoes - no official API listed, but they likely have some commercial version
4) IMDB - no official API listed, but they likely have some commercial version
I believe the current ratings are fetched from Traktr? I am not a fan of the current ratings, they don't seem to reflect my tastes, and I'm sure I'm not alone. I know it's highly subjective, but after watching 2-3.000 movies you tend to differentiate your tastes from the vast majority, which is why letterboxd or metacritic would be a valuable alternative, as they are tailored for hardcore movie lovers.
Accessing those APIs would probably come at a cost, but I'd be happy to pay an in app purchase if needed.
Thanks for considering!
PS: I think there's a thread for RottenTomatoes ratings, but I felt we needed a general thread for movie ratings. If you guys have any other suggestions or if you know the official API sources for the above let me know and I can update this post.