Mobile companion apps for AAA PC and console titles have become popular in the last few months: see companions for Call of Duty and FIFA 2013 for examples. Ubisoft's Far Cry 3 is a surprisingly excellent addition to the shooter franchise, and it offers a companion app for its multiplayer component. But what makes this one different is that it includes more than the standard social/organization elements: playing the Outpost app can score equipment and upgrades for the main game.
In Far Cry 3's online matches, players come across flash drives that can be submitted to Ubisoft's website to be "decoded", granting upgrades to weapons and equipment. These extras can be kept or traded. With the Outpost app, you can decode the flash drives from your phone, earning a little bonus XP for doing so. Of course, you also get the standard loadout modifications, plus challenges for bonus XP, and the ability to track the maps you've submitted.
The look of the app matches the game, and you can log in to your PC, PS3 or Xbox game through Ubisoft's Uplay service. There seems to be some serious compatibility issues with the 1.0 release, with plenty of users reporting regular force closes. Here's hoping it improves sooner rather than later.