I'd like to grant access to my site via Facebook, Twitter and so on. I will definitely need the user's email and hopefully his avatar image. I see the following algorithm:
- User clicking on "access via Facebook (or anything)" button
- Browser shows a pop-up with Facebook (or anything) login and password inputs
- User types in his login/password pair and clicks "Sign-In" button
- Something (it is not clear for me how) calls my script like
Probably there are any tools to make this routine clean and easy providing most common social networks (Facebook, Twitter, LinkedIn...)? Of course free tools will be much more appreciated.