It makes me sad to see this on hn. I would appreciate a technical write up on the implementation of this app but as snackai said, based on the screenshots it doesn't seem impressive technologically.
Quality rather bad. Also, what are you using an API for? Ever heard of Viola Jones? "Programmers" these days...
Thanks for your feedback.
Implementing a Viola Jones algorithm that is capable to detect tilted faces (and also assess the rotation) from scratch would rather resemble a PhD thesis than a weekend project for fun.
DLib has a good implementation of face landmark detection, closer to what you want to do than Viola Jones: