Looks cool. I think this is more suited to Instagram than Facebook. Even though Instagram is wildly popular, you still don't get to see as much third party tools like they have for twitter.
Also one question :
Would giving permission to post result in the app making postings without my knowledge?

I am using what they are sharing on twitter and facebook to gather these articles. Do let me know your feedback when you get a chance to try the app

Great concept. I love the clean design.