In our time, when the main camera is a favorite for many smartphone, vertically oriented video - a common phenomenon. To take out only in landscape orientation, you can use the Horizon application.
The basic idea is simple to genius: no matter how you turn your eye-device, the program will grab only the portion of the image that fits in a horizontal rectangle. The ratio of its sides, of course, is always equal to 16: 9, but what is interesting: due to changes in the area capture region is possible to realize the effect of collision and recoil chamber while the "operator" is a single point.
Of the additional programs can be called chips means the focus is locked, and the white point, and a set of built-in filters that allow you to shoot video at once in the style of "instagramchikov". Horizon supports two cameras integrated in the eye-device, - self-portraits, too, will be exclusively in the landscape orientation. ;)
The only thing over which the authors of "Horizon" still need to work hard - this is image stabilization. When moving, as well as by simply turning the device, the image begins to significantly shake. With this definition, it is necessary to do something, as implicit in the program idea certainly deserves a long and happy life in the App Store.
Price: Free
As a postscript - an indisputable truth. So that.