Casual Friday: An App That Tracks and Quantifies Your Sleep. Yes, Really.

I’ve talked about sleep before, and how it relates to health. I’m a nerd that way. I think sleep is important, and most of us don’t get enough of it and what we do get is often poor quality.

So, that said, can I tell you about something I like?

There’s an iPhone app called Sleep Cycle that purports to do what nigh borders on magic: track your sleep quality and report in the morning on how well you slept. How does it do it? The iPhone’s gyroscope, mostly, but I wouldn’t be surprised if it uses unicorn tears either, because what began as skepticism with me changed into full-on belief/amazement five days later. In a word, it works as promised, so much so that I have no choice but to echo the other reviews this app has received: it’s amazing.

The exact voodoo Sleep Cycle uses to determine sleep depth is a mystery, but again, at a basic level, it uses the iPhone’s gyroscope to detect movement. Increased movement = lesser sleep quality, but I’m sure there’s more math to it than that. In my experience, I found that the app perfectly tracks my cycles of being awake and deeply asleep.

Example: I get up at 3 AM to go to the bathroom. It knows and records it.

Another: I typically have my deepest sleep around 3:45 AM. I know this from 43 years of being alive. Sure enough, the app knew it in one day.

The concept is simple: you place your iPhone face down on the corner of the bed nearest you. The instructions say place it under the top sheet, but I don’t. You must leave your phone plugged in, because the iPhone is ‘conscious’ overnight as the gyroscope collects movement data.

That’s it. You go to sleep, and it goes to work.

When you wake up, you flip off the alarm (if you have it set; more on that later) and you get your sleep report card:

This is your sleep results dashboard: you can see your sleep quality hour by hour (ranging from awake to deep sleep), and after five days, the app will start giving you a percentage ‘sleep quality’ score based on what it knows about your sleeping (and movement) patterns. When you wake up, you can have the app ask you how you feel: good (happy face), average (normal face) or lousy (sad face). You an also set up sleep notes like ‘stressful day’ or ‘worked out’ or ‘had drinks’ and the app will start to correlate these notes with sleep quality scores.

Like most quantified-self apps, this gets better the more you use it. It’s database grows pretty robust, so your results get increasingly accurate over time. If you’re into poring over the raw data, the app even provides an option to show it to you in the Settings menu.

If you flip your iPhone to landscape orientation, you get a bevy of additional reports. Here are a few:

Sleep Cycle also has an innovative alarm function: it will wake you in a time range (say, 6:30 AM – 7:00 AM) when it detects you’re sleeping the lightest. That way, the logic goes, you’re not jarred out of a deep sleep, which tends to make humans wake up with bared fangs. It has a regular alarm too (which wakes you up at a static time), but from what I found, the smart alarm works as advertised.

What can I say? This app is modern-day magic, and you’re probably not getting enough sleep as it is. If you’re at all a performance nerd like me, you should stop reading and just go get it. You probably spent two grand on a fancy mattress, so spend a buck on this and see where it gets you. Available on the App Store.

(Full disclosure: I have zero financial interest or stake in Sleep Cycle. I just think it’s modern technology put to a good use, and a smartphone app innovation showcase. Plain and simple.)

Have a good weekend, everyone.