Ok I was able to copy the video back onto my android (via bluetooth) to the generic /movies directory then moved it back under .../com.harrys.laptimer/files/Movies. So within the Harry's app I see a red "!" next to the video now. I assume I need to re-link this? How do I go about doing that?

I copied videos off my phone, then deleted from. Then on my laptop I renamed them and tried to copy them back to .../com.harrys.laptimer/files/Movies, but now it won't let me. Is this because I renamed the videos?