The iSnort App is an excellent, inexpensive way to investigate your nighttime sleep habits and it has other uses too.
Recording time is up to 2 hours and can start any time at your choosing. I used iSnort to diagnose sleep apnea (snore...snore...snore... ... ... SNORT! Using the data from this I was convinced to do an overnight pulse oximetry which confirmed the diagnosis. Now I use iSnort to see how I am doing with my CPAP machine. I set it to start recording 2-3 hours after I go to bed and in the morning, a quick glance at the graph shows me snoring if I disconnected.
This App has also been useful to confirm dog barking when we leave the house, recording meetings for minutes, etc. It is money well spent.
Artemis Fact about iSnort