What app do you use to track your sleep?

I've used Sleep Cycle for the past two years. The statistics and trends are beneficial and allow me to understand what I can do to get better sleep. All of the trends the app shares are insightful and share when, as well as where, I get the best sleep. Fun fact: I've spent 8.2 months in bed ¯\_(ツ)_/¯

Probably the best app out there for Android. Works great with my Xiaomi Band 2. The "Smart alarm" feature works like magic waking me up in the most optimal time. Also couldn't get out of the bed without a having to take a picture of a QR inside my bathroom.

I use the Sleep Sensor that I put under my mattress because I do not like to sleep with a bracelet around my wrist. I like this technology is fully integrated in my daily life seamlessly :)

Works well on Apple Watch. Can write data to Apple Health (but paid version is required). Has alarm clock integrated with useful options (full recovery, nap, powernap etc). Beautiful charts :)

I have an Apple watch and this is the best app I've found so far for making the most of it and my iphone.

Allows to access sleep data from a Mi Band 2 in a greater extent than the Mi Fit app

I used to use it because it was free and had this great day-split week sleep timeline plot. Still missing it. Sadly, last time I used it it was a totally outdated piece of software with some problems.