If you've ever been in the position where you're unsure which film to watch out of a list of possible candidates then this app will help you choose.
Just add the films you're thinking about watching, seperated by a comma and click 'Check Films'. The app will then list the films in order of their IMDB / Rotten Tomatoes ratings along with a summary of what they're about and their poster image.
I wrote a blog post with more information about this site on my developer blog.