Pillow

Pillow is a good fit if you already wear an Apple Watch. You don't have to remember to start anything; it notices when you fall asleep and builds your night from the watch data.

You get a sleep stage chart, a score, heart rate, and on-device audio recordings of snoring or sleep talking. There's also a smart alarm, nap modes and a quick mood check when you wake.

You can track with just an iPhone, but it works best with the watch. Premium adds deeper analysis and CSV export.

Keep in mind that sleep stages from a watch are estimates, not a medical test. Pillow is most useful for watching trends over weeks, like how your bedtime or naps line up with how you feel when you wake.