Privacy Policy - Ulertu
1. Overview and Scope
Ulertu is an educational spreadsheet diagnostic application developed by Saifullah Ahad. It helps students, teachers, and spreadsheet learners understand how formulas evaluate and how cell values depend on each other.
Users can explore built-in sample workbooks or open their own OpenXML spreadsheet files (.xlsx, .xlsm). Ulertu analyzes formula dependencies locally on the device to create targeted prediction questions: if an input cell value were altered, how does a formula result cell change? Users test their reasoning and step through the full calculation trace.
2. Records Kept on Your Device
Ulertu requires no user account, sign-in, username, password, or contact information. All data processed by Ulertu is stored exclusively in the application's private internal storage directory on your phone:
- Imported Workbooks: When you open a spreadsheet through the system file picker or via the "Open with" or share intent from another app, a working copy is saved directly into the app's private files directory (
files/workbooks/) under a filename derived from its cryptographic SHA-256 hash. Standard Android file-sandbox boundaries prevent other installed applications from reading this private directory. - On-Device Database: An SQLite database (
ulertu.db) keeps records of your workbooks and diagnostic checks:- Workbook records: the display name, local file path, file size in bytes, SHA-256 hash, chronological sequence order, and check counts.
- Evidence records: the tested formula cell, formula expression, input cell that was changed, original and modified values, prediction prompt, available answer choices, your recorded answers, whether your prediction was correct on the first attempt, follow-up attempts, and step-by-step calculation trace chains.
Ulertu does not transmit workbook contents, formula structures, or quiz responses across a network. The app does not add a separate workbook or database encryption layer; Android app storage provides isolation from ordinary access by other apps.
3. Device Permissions and Network Behavior
- No Internet Permission: Ulertu does not declare the
android.permission.INTERNETorandroid.permission.ACCESS_NETWORK_STATEpermissions in its Android manifest. The application cannot establish network connections, transmit telemetry, or contact remote servers. - No Dangerous Permissions: Ulertu requests no access to device location, camera, microphone, contacts, call logs, calendar, SMS, physical activity sensors, or shared storage.
- System File Selection: Opening a workbook uses the standard Android Storage Access Framework (SAF) and system intent mechanism. Ulertu receives temporary read access only to the single file you select.
- Other Providers: Files selected from another app or a cloud document provider remain subject to that provider's privacy and retention practices. Ulertu does not control the original file or other copies.
- Android Backup Excluded: Ulertu disables Android backup and declares explicit cloud-backup and device-transfer exclusions on Android 12 and later. This does not remove historical backups made outside Ulertu.
4. Advertising, Analytics, and Third-Party Services
Ulertu contains no advertising SDKs, no behavioral tracking, no third-party analytics libraries, and no crash-reporting services. The application does not collect, profile, sell, or share personal data with any third party.
5. Retention and Deletion of Data
All imported workbooks, check counts, and diagnostic history stay on your phone until you delete them:
- Deleting a Single Workbook: In the "Your workbooks" list, selecting "Delete" removes the app's saved workbook copy and associated answer-history records. It does not delete the original file, provider copies or historical backups. This is not a claim of forensic erasure.
- Deleting All Workbooks: Selecting "Delete all" removes every imported workbook file and clears all check history from the database.
- Removing the Application: Uninstalling Ulertu or clearing its storage in Android Settings removes app-local workbooks, history and settings. Copies held elsewhere must be removed at their own destination.
6. Children's Privacy
Ulertu is intended for learners aged 13 and older. It does not request a learner's name, age, school, email address or account registration. A workbook may contain personal information entered by its author; choose files you are permitted to use. The developer receives no workbook contents or learner history.
7. Updates to This Policy
If features or technical behaviors in Ulertu change, this privacy policy will be updated accordingly. The effective date at the top of this document indicates when the latest revision took effect.
8. Contact Information
For questions or inquiries regarding this privacy policy or the application: