While I like the app and what you're trying to do, just a heads up that you're going to come across as super shady by automatically following the @glu Twitter account when you have users login with their Twitter credentials. The problem is that you're not making it clear up front that by logging in, you're going to be adding a follower to their Twitter account, which will be interpreted as a violation of their privacy, and will almost certainly cause a backlash at some point.

I understand that in order for your app to work, the user has to be following the @glu account, but automatically opt-ing someone in is not the right way to do it. You need to update the content and design to make it painfully clear to anyone logging into your site that they are also consenting to following the @glu account.