BlockTracker is a private, personal app used only by its owner.
What it accesses: read-only access to the owner's Google Calendar events
(Google scope calendar.readonly). It never creates, changes, or deletes events.
Where data goes: calendar data is read by a server on the owner's own computer and sent only to the owner's own iPhone, through Apple's push notification service. It is not sold, shared, or used for advertising, and no other person's data is collected.
Removing access: access can be revoked at any time at myaccount.google.com/permissions.