I guess it's really safe cause it's open source, you can make notes on your habits but don't really do that. Its simple. Really fast. Haven't found a way to connect it to notion. In general it's a great app to track you habits. Does its job. Not more, not less.
Mi Fit - Mi Fit is a band to monitor your health and fitness level on daily basis.
Habitica - Habitica is a free habit building and productivity application.
Strava - The #1 app for runners and cyclists
HabitBull - HabitBull
fitbit - The Fitbit mobile app is for people who use Fitbit fitness trackers to keep track of their activity goals, food plans, and other fitness related things. Read more about fitbit.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.