Anybody have any idea how I can record video on my phone, using my mic running through my interface for the audio? If it matters, the phone's android and the interface is a Presonus Audiobox.

I would just record the video and audio at the same time, separately, then bring them together in a video editing software. Mute the original video's audio, though.

Clap at the beginning so you can sync up the audio and vidya.
I think you might need one of the IK input cards for Android, unless the Presonus has interface for that (I think it has Thunderbolt for iMac, iPhone and such, at least the new model does). Just make sure you research with them that your phone will work.

If you're recording to video from phone and audio into a PC, just use 4 count clap or something.
The problem before was that I was planning to do something that stipulated no overdubbing. I'm probably not doing that anymore, so for general use I'll just use the clap thing.