Hey Katie! This is such a cool feature but I haven't tried it yet. I know MLB always stays on top with technology and apps so it doesn't surprise me. Let me know if you try it!
At the Mets game Sunday, I used the App and found it quite helpful but they dont have the upgrade option yet. Was looking for the option to turn on the heat as we froze at the game...
Here a a breakdown of the app and the new features. http://mlb.mlb.com/mobile/attheballpark/