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.
ContinuSys - ContinuSys Integrated Business Management System (IBMS) is a suite of cloud-based integrated apps that help manage all parts of your business efficiently.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Pearl - Transform your photos into narrated storytelling videos
HabitBull - HabitBull
Shared Albums by Google Photos - Share photos & videos between friends and family