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.
Expensify - Import expenses directly from a credit card to create free expense reports quickly. Approve reports online and reimburse directly to a checking account with one click.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Abacus - Expenses without the 'expense report'
HabitBull - HabitBull
Fyle - Track expenses across devices on-the-go and maintain a central repository. With custom approval flows, automatic policy violation detection and an automated audit trail, be audit-ready at all times!