chat website, RTL langauge including facebbok users integrat

Hi, Looking to build a chat site, RTL languge. Users can be login with their facebook users or with unique users. Design needed too. The site will give the adminitrator the ability to throw away users that are not behaving well and, of course, to manage the pages and chat rooms. Facebook users can open private rooms and order their facebook friends to get in. rooms managers can also decide which user get in. Please write wether you can develope smartpohnes apps to get into the chat rooms also and it's costs.