But what are Horizon's limits? Its creators wanted to find out. This week, using some cardboard, tape, and twist ties, they fastened an iPhone to a car's wheel and drove through a parking lot recording video with Horizon.
The end result is pretty awesome, if a little trippy.
The video can't stay perfectly straight, founder Stelios Petrakis writes in a blog post, because the centrifugal force from rotating around the wheel caused the iPhone to lose its usually-constant sense of gravity. As a result, straight lines like curbs and street laps wobble.
The experiment got pretty extreme: the founders tested the app at speeds up to 31 mph. Though the faster they went the more things got out of whack, Evil Window Dog says a future update to Horizon should help the app fair better in the stuck-to-a-wheel test.