Companion Apps feel like the future of gaming, and that's awesome
As passive experiences, Second Screen apps for gaming are a "take it or leave it" kind of deal. They are nice to have if you are really into a game, or if you're particularly social on one gaming network or another, but most of these apps aren't giving you any sort of edge in the game. The few apps that stand out in this category are most commonly referred to as Companion Apps. These apps are designed to create an experience that is in the same world as the core game, and in many situations is played during the core game, but the look and feel to these experiences make it easy for a second player to act as your wingman and play by your side.
For a little while now, all of the major gaming platforms have tried to encourage these Companion experiences. Microsoft built support for the experience into SmartGlass, Nintendo showed off an example of this experience when the Wii U first launched, and PC gaming is all but built for this kind of thing to be bolted on to just about everything. It's not hard to see why the more traditional Second Screen apps would be preferred, as they are cheaper to make and maintain, but Companion experiences really do enhance the entire game. This kind of gaming is still in its infancy still, but the few examples that we do have out there are a ton of fun.
The best all around experience that exists in this category today is the Xbox SmartGlass exclusive Boss Mode part of Plants Vs. Zombies: Garden Warfare. This game had already managed to turn the PVZ franchise on its head by existing as a first-person shooter, but when you have someone sitting by your side in Boss Mode you can often gain a considerable advantage. Boss Mode creates a new character that flies above the battlefield and gives the player a top-down map of the action. You can see where each player is, and through this experience can deploy healing/resurrection accessories, as well as call down brutal airstrikes to help secure an area on the map. In return, players on the ground can see you in the air, and if they so choose can attempt to shoot your down. It's a flawless accessory to an already fun game, and adds a unique dynamic that could easily be seen in other games in the future.
There are less active versions of this experience through other games that are designed for single player use, but a second player could easily take the helm and make your gameplay a little smoother. The two biggest examples are the Battlefield 4 Commander app and the ctOS app for Watch_Dogs. The Commander app lets you join a game and assume command over troops and vehicles from your tablet, using a top-down map to offer perspective that the other players simple don't have. Meanwhile, ctOS takes the larger theme of Watch_Dogs into as real an experience as they can offer by putting your Android device in control of the city itself in order to mess with other players. It's a unique take on the Companion experiences, and likely the direction we'll see more games head over the next year.
Last, but certainly not least, we have the Puppet Master Mode in Just Dance. This game mode is unique to the Wii U and Xbox SmartGlass, and as the name suggests puts someone who isn't dancing in control of the folks who are. Puppet Master Mode lets an observer change things up a bit and made individual players do different things in the game to enhance their scores. These scores are determined by the person holding the tablet or Wii U gamepad, and generally speaking takes a multiplayer experience and moves it so there's a consistent set of random new challenges built around the social interactions of the room. It takes a regular game and modifies it in a way that can't be accomplished in software alone, at least not yet.
As gaming consoles become more connected to the other tech in our lives, and PC gaming looks to extend beyond the existing experiences with things like the Oculus Rift and connected space controllers, we're going to see more of these Companion-style Second Screen apps come to life. With all of the sensors in our phones and the sheer power found in new processors, our tablets and smartphones become ideal partners in the future of gaming. All you need to do now is decide what the best kind of stand will be so your Android device is never far from reach during gameplay.