The Camera app on some iPhone devices makes it possible to shoot slow motion (slo-mo) video with a high frame rate.
Unfortunately, slo-mo videos from the device are intentionally mis-marked with the wrong frame rate so that they will play back in slow motion. The mis-marked times are brought into Video Physics. As a result, when the video plays back in Video Physics in slow motion, the time values are based on 30 frames per second rather than reflecting real-world time.
In short, the issue is a mismatch between the needs of photographers and physics teachers. Physics teachers and students will need to apply a time unit correction after the fact to any analysis.
In the future Video Physics may offer a manual frame rate override, but this feature is not now available.