Yes. The app works fully offline, and your notification history, alarms and settings stay on your phone. They are never uploaded.
What goes online
The app uses the internet only for things that are not your data:
- Ads in the free version
- Google Play purchases
- Crash reports and basic usage statistics (Google Analytics). These never include your notifications or messages.
What it doesn't do
- It doesn't read your contacts or access your files.
- It creates backups only when you ask for one, using the secure Android file picker.
You can read the full details in the Privacy Policy on notificationtracker.com.