I've been using this one [0], which lays under your mattress and is surprisingly accurate (have many night time wakings due to young kid). It tracks movement, even heart rate and snoring.
You don't have to charge it, nor wear anything, which is why I got it vs. any of the wearables.
You don't have to charge it, nor wear anything, which is why I got it vs. any of the wearables.
[0]: https://www.withings.com/mx/en/sleep