According to reports on Twitter, some developers had been unable to use the app to view session videos following the security breach on Apple's Developer Center that shut it down for an extended period of time in July 2013.
Apple's WWDC app was also used for the evasi0n iOS 7 jailbreak, and it is unclear if the new update also has something to do with that.This release addresses an issue where developers were unable to log into the app to watch videos. Thank you for your bug reports and feedback.
WWDC can be downloaded from the App Store for free. [Direct Link]
Article Link: Apple Updates WWDC App with Video Fix