This is pretty incomprehensible. Why doesn't someone from twitter or the documentation please just explain what the callback URL is? What's supposed to be at the other end of that URL? Do I just make something up, and it magically works? If so, what's the point?
I've been a developer for 20 years, so this is not a "clueless new dev" situation. This is a "your documentation is so lacking as to be utterly worthless" situation.
It obviously has something to do with the oAuth process, but just as obviously there's no documentation as to what it's supposed to be and whether or not it's required for non-web situations (connecting for Twitter login via Parse.com for a client's app, in my case).
If you want people to use your framework for login (and you clearly do) then why the heck don't you provide ACTUAL INSTRUCTIONS for making use of it??!
Frustrating as hell.
Hate twitter just a little more today than I did yesterday.
Spectacular job on the developer relations front, team.