Review of Sleep Cycle iPhone App

Every once in a while, an app comes along for the iPhone that seems way, way too good to be true. Enter the Sleep Cycle app, which claims to be able to track your sleep patterns. It sounds pretty dubious at first, but at $2, I decided to check it out--after all, it's gaining immense popularity on the iTunes App Store.

Here's my full review of the Sleep Cycle iPhone App.

Functions

The Sleep Cycle application uses the iPhone's built-in accelerometer to track your movements as you sleep, and estimates from that data what time you went to sleep, when you'd gone into the different stages of sleep, etc. It even includes an alarm to wake you up in a light stage of sleep, the idea being that you'll wake up more refreshed in these stages. This alarm operates within 30 minutes of the time you set it for--meaning that an alarm set for 7:30 could go off at 7. But hey, you'll be more rested, so it's worth it, right?

In order to use the Sleep Cycle app, you've got to sleep with your iPhone next to you, which might seem odd to some people. The iPhone also needs to be face down, and placed in a position where it can detect every movement you make. That means that in some cases--for instance, if you're sleeping on a couch because your girlfriend is tired of you testing your iPhone while she's trying to sleep--you can't use Sleep Cycle.

Tests

Of course, the only way to check the Sleep Cycle app with 100% accuracy would be to run a sleep study properly and compare the results. That's fairly impossible, so I decided instead to use Sleep Cycle for three nights with varying conditions, to see how well the tracking element worked. For example, I'd set an alarm for the middle of the night, then get up and turn that alarm off. The next day, I checked the Sleep Cycle graph, and sure enough, my late-night move over to the alarm clock and back was logged.

What's more, Sleep Cycle seemed accurate in other respects. I woke up one night after a dream, and Sleep Cycle had fairly accurately estimated when that dream was happening (and when it ended). The iPhone app's accuracy is comparable to an expensive sleep watch, making it well worth the price for anyone curious (and anyone with a sleeping disorder).

The only problem I had with Sleep Cycle was the alarm, which is fairly quiet. I also was prone to going asleep again after the alarm went off, so I'm still somewhat skeptical of whether a person could use the app to shorten his or her sleep cycle. You could certainly diagnose sleeping problems with it, though, and overall I found Sleep Cycle to be an awesome app that works exceptionally well. Put this on your iPhone must buy list as soon as you can.

Have you tried Sleep Cycle? Post your thoughts in the comments section below.