I found out that I can record iPhone video through USB with OS X Yosemite. It’s a bit annoying that I have to play tethered to my laptop, but I’ll stick with it for the simplicity and superior quality. The only annoying thing is that the time at the top is static and I’m not sure if I can change that.
I tried adding some music and took some liberties with speeding up the video through some thinking time to match the song’s duration. It doesn’t feel quite right to do so, but I’d rather have a video with music than not. Maybe in the future I can mark the areas where I sped things up.