Ritual keeps your tasks, journal, settings and site-time history in your browser. Nothing is sent to the developer, and there are no analytics or ads.

Ritual only contacts outside services you choose to connect:

Google (if you sign in): reads your calendar events to show your day, and saves a backup of your Ritual data to your own Google Drive.
Todoist / Google Tasks (if you connect them): reads and updates the tasks you work on in Ritual.

These connections use your own accounts, and the data goes only between your browser and those services. You can disconnect at any time in Settings, and turn off journal backup in Journal settings. To remove everything, use Settings → Data or uninstall Ritual.