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.
Box2D - A 2D Physics Engine for Games
HabitBull - HabitBull
Bullet - Share captioned video snippets of podcasts from any app
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Matali Physics - Matali Physics is an advanced, multi-platform, high-performance 3d physics engine intended for games, virtual reality and physics-based simulations.