Horizon is a new video-recording app from Evil Window Dog that shoots your video in horizontal mode, regardless of how you hold your phone. It's a lifesaver for those spur-of-the-moment shots when you accidentally pick up the camera and start recording in the wrong orientation.
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 viewport box does tilt as you rotate your phone, so you want to avoid rotating while recording. If you tilt while you shoot, the area that is being captured will adjust in response to your movement. As a result, your video's field of view will expand and contract as you move. Horizon is best suited for filming with your phone in one orientation per clip.
Options within the app are plentiful, but not overwhelming. You can toggle between the front and rear camera as well as turn the flash on and off right from the main screen. You can change the size of the viewport from a smaller, fixed frame to an extended frame that takes up most of the screen. If you want to shoot in portrait mode for effect, you can even disable the horizontal lock. Within the settings, you can also change the resolution of the video with values that range from the maximum 1080p to the lowest 480 x 480. Last but not least, there are filters that you can apply in real time.
The quality of the video that I recorded was very good, as good as the iOS Camera app in most circumstances. The only problem I noticed was that, when compared to the iOS camera, some videos from Horizon had a noticeable amount of shake. I saw it primarily on close-up shots -- for example, when I was filming my favorite coffee cup to see how the app captured colors and maintained focus. The shake was not noticeable when I was filming my kids playing outside.
I believe the shake was the result of my filming technique, but it's something you should be aware of. When filming, I discovered that I focused on the viewport box instead of the phone. The viewport box moves slightly as you move, and I was always trying to keep the box straight. I believe I was inadvertently moving the phone enough to introduce some shake into the video. This didn't happen in the iOS Camera app as I focused on the whole frame of the video and didn't move the phone as much.
Horizon is available for US$0.99 from the App Store. It's a universal app that supports the iPhone 4s or newer, the iPod touch fifth generation, the iPad 2 or newer and iPad mini or newer.