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.
Pliim - One click and be ready to go up on stage and present!
HabitBull - HabitBull
Hidden Bar - A ultra-light MacOS utility that helps hide menu bar icons.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Hocus Focus - A Mac menu bar utility that hides your inactive windows