The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From Subaru of America:
See what you and your friends look like under high g-forces with Gs Your Face from the 2011 Subaru WRX and STI. You take a picture, then get to see what happens when youre under the g-forces of a rally-bred sports car. Heres a hint: it aint pretty. Just take a picture, record yourself saying Geez, shake your iPhone, and enjoy as the subject of your photo is warped by the effects of high Gs. Playback the audio to hear the voice warp as well. The harder you shake, the greater the Gs. And Geez. Features: A G-meter that rates the level of g-forces applied. Share pictures with your friends via email or Facebook and Twitter. A post-to-Flickr function that allows you to add the photos to your photostream. Now you can subject yourself and friends to high Gs, just like you would in a WRX or WRX STI. Just download the app and Get more Gs.