This app was mentioned in 4 comments, with an average of 2.00 upvotes
PAX takes place across 7 buildings. The curse of it being in Seattle, where the convention center simply isn't big enough. However, an expansion is in the works. By 2020, it'll double in size.
You can download the Guidebook App to quickly look at the show maps, exhibitor lists and panel info.
Android: https://play.google.com/store/apps/details?id=com.guidebook.apps.PAX2014.android
iTunes: https://itunes.apple.com/us/app/guidebook/id428713847?mt=8
The '<em>PAX Prime 2015 Mobile App</em>', I think this is the official app. I only really downloaded it to check whether OP was right or not.