A new app called Horizon has just made it into the App Store and it always shoots wide shots, whether you hold it in portrait, landscape, or even sideways.
"While many apps like Instagram offer straightening in photos, Horizon is the first app to do this on video and in realtime," Evil Window Dog, the development studio who built the app, said in a press release. "As the user records, Horizon autolevels videos utilizing the device’s gyroscope. The orientation of the resulting video stays corrected so that it is always parallel to the ground."
Horizon uses a neat trick to always record in horizontal mode. The app has a rectangular indicator that always stays in the center of screen. It's within this viewport that the Horizon app is capturing. No matter how you rotate the device, this box stays centered on the screen. When you start shooting in portrait mode, for example, all you will capture is the horizontal content within the viewport.
The iOS app (it runs on iPhone 4s/iPad 3 and above) has other features as well, including Instagram-like filters and the ability to capture in multiple resolutions. You can find it in the Apple store now.