I tried tracking my sleep using 3 free Apple Watch apps - and there was a clear winner

Pillow, another app I recently tested, can show how long you've slept, the quality of your sleep, the amount of time you spent asleep, and a breakdown of your sleep stages (i.e. light, deep, REM, awake). It also shows your average, maximum, and minimum heart rate during sleep. But its free offerings aren't nearly as comprehensive as SleepWatch's, which lets you see trends over time and personalizes the experience based on how you're feeling and your health conditions.

Pillow also records sounds so that you can keep track of whether you've been snoring, but you'll have to pay to hear them and view overall trends and statistics over time. The one-time $5 payment also gets you personalized recommendations on how to improve sleep, new modes for measuring naps, and additional alarm sounds and melodies among other features.

Sleep++ is a basic tracker that provides you with a look at your total sleep, how much of your night was divided between restless and restful sleep, the amount of time spent awake, and your best sleep window.

The app also sends a notification summarizing the quality and duration of your sleep in the morning, allows you to set a nightly sleep goal, and can send you bedtime reminders. For $1.99, you can strip out the app's ads.

While I appreciated the simplicity of the app during my time using it, Sleep++ feels bare bones in comparison to SleepWatch.

Sleepzy and Sleep Cycle, which I didn't have the chance to try, also offer sleep tracking free of charge.

Sleepzy is a hybrid of an alarm clock and a sleep tracker. You can set an alarm directly within the app and view statistics such as time spent asleep, the quality of your sleep, time spent in REM, light, and deep sleep as well as time spent awake, changes in heart rate, and time spent in bed versus your sleep goal. What also makes Sleepzy stand out is its ability to track sleep debt, perhaps providing more motivation to get to bed on time.

The app can also record any sounds you make throughout the night so that you can keep track of whether you're snoring. But like Pillow, you'll have to upgrade to a paid subscription to listen to these sounds, view more advanced statistics, and track your progress over time.

Sleep Cycle also provides a graph that depicts the quality of your sleep, the amount of time spent in bed, and how much time you've spent awake and in deep sleep compared to regular sleep. You can also set an alarm within the app, just like in Sleepzy. Sleep trends, however, are only available to premium users who pay $29.99 per year. Unlike other free sleep-tracking apps, the basic version of Sleep Cycle does not measure your heart rate either.