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.
Mimo - Learn how to code on your iPhone📱
Habitica - Habitica is a free habit building and productivity application.
Quick Code - Curated list of free online programming courses
HabitBull - HabitBull
Enlight - Performance and Error Monitoring. We keep an eye on your applications and notify you about performance issues and errors.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.