Privacy Policy for Chartdo
Last Updated: November 9, 2025
Introduction
Chartdo ("we", "our", or "the app") is a weight tracking application developed by Prozwen. This privacy policy explains how we handle your information when you use our mobile application.
Our Commitment to Privacy: Chartdo is designed with privacy as a core principle. We believe your health data belongs to you and should remain under your control.
Information We Collect
Data You Provide
When you use Datagraph, you may provide:
- Weight measurements (values and units)
- Timestamps (when measurements are recorded)
- Optional notes (text you add to weight entries)
- Camera images (temporarily, for OCR processing of weight scales)
Data Stored Locally
All your weight tracking data is stored locally on your device in an encrypted database. We do not store your data on our servers.
Camera and OCR
When you use the camera feature to capture weight from a digital scale:
- Images are processed locally on your device using Google ML Kit
- Images are temporarily cached only for OCR processing
- Images are automatically deleted after processing
- No images are transmitted to our servers or third parties
- OCR text recognition happens entirely on-device
How We Use Your Information
We use the information collected to:
- Display your weight tracking history and trends
- Calculate statistics and generate charts
- Process weight scale images to extract numeric values
- Provide unit conversion (lbs/kg)
- Export your data for your personal use
Data Storage and Security
Local Storage
- All data is stored locally using Android Room database
- Data is protected by your device's security mechanisms
- Data remains on your device and is never transmitted elsewhere
Backups
- Android system backups may include app data if enabled on your device
- You control backup settings through your device's system settings
- We recommend using device encryption for additional security
Third-Party Services
Google ML Kit (OCR)
We use Google ML Kit for on-device text recognition to read weight values from scale displays:
- Processing occurs entirely on your device
- No images are sent to Google servers
- Google ML Kit may collect anonymous usage statistics
- See Google's Privacy Policy for more details
No Analytics or Advertising
- We do NOT use analytics services
- We do NOT display advertisements
- We do NOT track your usage behavior
- We do NOT collect identifiable information
Data Sharing and Disclosure
We Do Not Share Your Data
- We do not sell, trade, or rent your personal information
- We do not share your data with third parties
- Your weight data remains private and local to your device
Legal Requirements
We may disclose information if required by law, such as:
- To comply with legal processes
- To protect our rights or property
- To prevent illegal activities
However, since we do not collect or store your data on our servers, we have no data to disclose.
Your Rights and Choices
Data Control
You have complete control over your data:
- Access: All your data is accessible within the app
- Export: You can export your data at any time
- Delete: You can delete individual entries or clear all data
- Uninstall: Uninstalling the app removes all associated data
Permissions
The app requires the following permissions:
- Camera: To capture images of weight scale displays (optional feature)
- Storage: To save exported data files (when you choose to export)
You can revoke these permissions at any time through your device settings.
Children's Privacy
Chartdo is not directed at children under 13. We do not knowingly collect information from children. If you believe a child has provided data through our app, please contact us.
Data Retention
- Data is retained locally on your device until you delete it
- Temporary camera images are deleted immediately after processing
- Data is removed when you uninstall the app
International Data Transfers
Since all data is stored locally on your device, there are no international data transfers.
Changes to This Policy
We may update this privacy policy from time to time. We will notify you of any changes by:
- Posting the new policy in the app
- Updating the "Last Updated" date
- Providing in-app notification for material changes
Your continued use of the app after changes indicates acceptance of the updated policy.
Contact Information
Your Consent
By using Chartdo, you consent to this privacy policy.
Summary - Key Points:
- ✅ All data stored locally on your device
- ✅ No cloud storage or servers
- ✅ No data collection by us
- ✅ No analytics or tracking
- ✅ No advertisements
- ✅ Camera images processed on-device only
- ✅ Images deleted immediately after OCR
- ✅ You control all your data
- ✅ Export and delete anytime
This privacy policy is effective as of November 9, 2025.