A new app, currently on sale for $1, promises to fix one of the plagues of modern life — “portrait” videos. Horizon, an alternative video camera app, forces the video camera to capture in landscape mode regardless of which way the iPhone is positioned. The on-screen preview allows users to focus on the horizontal crop of what they are shooting when holding the iPhone in portrait, and offers web-quality VGA, 720p or 1080p quality along with square, 4:3 or 16:9 aspect ratios….