Before I start going on and on about how just versatile and useful Roccat's app will be, I'll get the one major catch out of the way first: This product isn't for a Mac. It does of course use an iPhone, but the app ties over wi-fi into a desktop app that, Roccat has confirmed, is only going to be available for PCs. Mac compatibility is a remote future possibility, but Roccat told me that "it will take some time" -- the company has a long history of Windows accessory customization, and not so much with OS X. So for now, the Power-Grid service will only work using the iPhone app to control and PC and the software on it.
But if you do happen to use a PC with your iPhone, you'll love what Power-Grid can do. Just as we heard last year, the app will have a series of screens with control buttons on them, and those controls will hook into PC functions. One screen will be full of various status updates (tracking your PC's CPUs, RAM, hard drive space and so on), and some of those controls will be interactive (tapping on the C: space listing, for example, will open up a Windows Explorer window on the PC set to the C: directory).
A sound control screen will offer access to system audio, including the main volume as well as sliders for mic volume and other options. There's also a controller for your music client that Roccat says will work with all of the major players, including iTunes.
Another screen will have updates from various social networks and programs like Twitter, Facebook, TeamSpeak, Skype and even RSS feeds, so you can browse through everything while a game is running on your PC's screen. And a final screen is called the "News Center", and will feature a series of curated feeds (including great blogs like TUAW, Joystiq and Engadget) and content to include if you want. Any of these tabs can be deleted or moved, but those are the main core tabs available to everyone.
Where the Power-Grid gets really interesting, however, is after the default tabs. First up, Roccat will offer a number of other tabs built to offer functionality in various games or apps. I was able to play with a Skyrim tab, for example, that offered macro buttons on the iPhone to do things like change the game's camera, or bring up the skills or map screen automatically. The whole thing was surprisingly responsive: Just pull up the Skyrim tab on the iPhone, hit a button and then immediately the effects appeared on screen. And thanks to Roccat's experience with keyboard macros, the iPhone buttons are very powerful: One button toggled moving in the game, and another one attacked with a weapon or cast a spell, which put a surprising amount of functionality just on the iPhone.
There are also tabs like that planned for League of Legends, Starcraft (think of just setting up a production queue by tapping a button on your phone), and a number of other games. And there will be a few non-game tabs available as well, according to Roccat, including functionality for Word, Photoshop and other popular apps.
But even that's not the most interesting part. Tabs can also be custom made by users button by button, through a very simple process of first setting the button's attributes, and then just dropping and placing it on to the tab and syncing up to the iPhone app. Anything you can do on your PC with a keyboard can be placed into a button macro, and then you can drag and set that button up however you like, turning your iPhone into a custom-made controller for your PC. It's really unbelievable, and even if you don't have the time or interest to create a custom tab for yourself, users will be able to share and favorite tabs online, so you can just wait until someone else makes the one you want.
The Power-Grid was an interesting idea when I first heard about it at last year's CES, but it's about to become a really incredible reality. Roccat said the biggest difficulty right now is getting Apple's approval on the whole system, but hopefully we'll see both the PC desktop app and the iPhone app (both of which are set up to be free!) available within the next few weeks.