The application should have a delay timer, like the one on the timer, and then record (probably for 6-8 hours).

The end recording should be automatically "cropped" with 10 second "chunks" over a certain average decibels left in.

I'm not sure if the "average decibel" method is the best way of doing it, but the idea is to make a long recording but only keep segments where there is audible talking.

There should also be a screen with a list of recordings, sorted by date.