Apps Are people using sleep tracking apps and happy with them?

[honglong1976]

I tried this and it seems to be working ok cheap and automatic sleep tracking, matches pretty much what my Fitbit Blaze shows for sleep and no battery drain either! (charge to 100% at 8pm, sleep, wake up 89% left)

https://itunes.apple.com/gb/app/sleep-tracker-auto-sleep-cycle/id1179236591?mt=8