Ok, so I've currently implemented Facebook login in my app the following way:
I use the official FB framework to login the user. When I login, I get a authentication token, which is sent to my server. I then do another verification of the user (e.g. get "me" from Facebook, using the auth-token), and then return 32 char random key, which is used to identify the user in subsequent API-calls (to my server). An example.
I'm trying to figure out how to do the same with twitter, but I can't understand how to get the oath token in iOS? I have the server-side part working in another app, but no token to verify...
Please advice – is this (the FB way) how I should be doing this, or how would you go about the verification process?