From the App Store description:
Make the most of the Apple Worldwide Developers Conference with the WWDC app. Even if you can’t join us in San Francisco, you can still follow along each day — session videos are just a tap away for all Registered Apple Developers.
• Browse times, locations, and descriptions for sessions, labs, and special events
• Mark schedule items as favorites with a simple double-tap
• Watch session videos, available daily
• Start watching on one iOS device, and pick up where you left off on another
• Keep up with the latest news, get important notifications, and see daily snapshots
• View maps to find your way around Moscone West
• Provide feedback on session content and speakers within the session details view
• Add your attendee information to Passbook for speedier on-site registration
As noted by MacRumors, new this year is video integration. All Registered Apple Developers will be able to watch session videos from the conference as they are posted. Typically, devs have to wait until after WWDC for Apple to post the useful clips.
At any rate, it looks like this app will only come in handy for folks attending WWDC, or at very least are Registered Apple developers. And if you fall in that category, you can find it in the App Store, for both the iPhone and iPad, for free.