According to the description in iTunes App Store:
The official companion app for THE HUNGER GAMES from Lionsgate Entertainment will get you exclusive, behind-the-scenes access to the disc production and keep you informed as the date approaches.
++ EXCLUSIVE CONTENT. Go back stage with the development of special features for the app that will be added as the release date approaches.
++ FANNOTATE. Be the first to create and share viewer commentary tracks with your friends.
++ Gestures. Flick your device to navigate the Blu-ray onscreen menus, or drag-and-tap our natural replacement to the traditional 5-button compass.
++ Discovery. Know more about what you’re watching. Get detailed notes, actor information, dates and more.