Getting the Twitter username of an already logged-in user



I wan’t to get the user’s Twitter account name - the one with the @ as it’s unique and static - for a highscore list in games in whatever languages. I don’t care about logging them in just get the name if they are already logged-in or open Twitter’s sign-in window first and then get the name if the log-in was a success.

I know very little about the new API - and find it hard to understand - but I presume there is a way for this maybe via sending a request to some webpage or such.