Want to create a Facebook app for auto share posts on the wall

Ok, this is the deal. I just launched a website working on WordPress where users can register, either from the site or by a facebook account, and share videos and images with the community.

What I want to do now is to create an application that lets user to publish their posts automatically on their facebook walls, if their accept the request of course.

I was looking on google for days and I didn’t find anything. This is freaking me out!

Any idea?

Thanks in advance!