Sleep is a complicates issue that can be addressed by every methods.
For general sleep issues Autosleep looks pretty good and I've just bought it.
My problem was snoring combined with an irritated wife with a sharp elbow.
Even cheaper (Free) is having someone with a stopwatch in the room with you as you happily snore away. Time the length of tine you simply sleep & snore and then the length of time you stop breathing/snoring. You'll start up with a "snort" and start snoring again. Any time you stop breathing for longer than 10 seconds. you are having an "event".
If you can't find someone willing to time you when THEY could be sleeping then get an old cassette tape recorder with a 2 for tape and record yourself. That could be scary.
I read that the "Pillow" sleep tracking app will record noises at night while you sleep, and you can listen to them later in order to see if you’ve been snoring or if it was the cat that woke you up. It is technically free, but it’s really not of much use without the $4.99 in-app purchase. Without that, you get a very limited sleep history.