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.
Habitica - Habitica is a free habit building and productivity application.
Crossroad - Don’t chase after your friends’ pictures anymore
HabitBull - HabitBull
iNZDR - iOS Live Photo Social Media app. Post and watch!
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
One Touch Share App - Streamlined photo and video sharing made interesting