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.
SMMRY - Summarize articles, text, websites, essays and documents for free with SMMRY.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
TLDR This - Automatically summarize any article or webpage in a click.
HabitBull - HabitBull
Free Summarizer - Summarize *any* text online in just a few secs. *MAGIC*