Hi Tomáš, thank you for the detailed review! We are the human-computer interaction group at Brown University, and we do research on projects related to this topic, so we found this very helpful. We actually built an app (only for Android right now) that lets you track your sleep and run experiments on yourself to see what helps you sleep better. We do not focus on long-term tracking, so the app looks different from most of the ones you have reviewed already, but we would love for you to try ours as well and let us know what you think! We wrote a post about it: https://medium.com/@brown.university.hci/sleepcoacher-how-to-complete-your-2019-resolution-to-sleep-better-one-self-experiment-at-a-time-a6237ce2ec3c Thanks!