August 12, 2026
Policy Sections
Overview & Account Policy
SimpleCalculator ("we", "our", or "the App") is a multi-functional utility application for Android devices developed by Katrex Technologies. This Privacy Policy discloses our practices regarding data privacy, features, third-party integrations, and device permissions.
No User Account Required: SimpleCalculator does not require sign-up, registration, user accounts, or login. We do not collect personally identifiable information (PII) such as your name, email address, phone number, or physical address.
Calculator & 60+ Converters
The App includes a basic and scientific calculator alongside over 60 financial, health, and unit converters.
All mathematical computations and unit conversions happen 100% locally on your device.
Calculation history is stored locally on your device via Android SharedPreferences and is never transmitted to external servers or cloud services.
AI Problem Solver (Camera Feature)
SimpleCalculator includes an AI Problem Solver feature that allows users to scan math equations or text problems using the device camera.
On-Device Text Recognition (OCR): Photo text extraction is processed entirely on your device using Google ML Kit OCR. Captured photos are NEVER uploaded, transmitted, or stored outside your device or session.
Step-by-Step AI Solutions: Only the extracted text string (and never the photo) is transmitted to a third-party AI API (NVIDIA AI API at build.nvidia.com) to generate step-by-step solutions.
Reference Learning Links: Users may choose to view external educational resources (such as YouTube, Khan Academy, or Wolfram Alpha) to further study step-by-step solutions.
Private Vault
SimpleCalculator provides a Private Vault feature that allows users to import photos, videos, and documents into an app-private, passcode/biometric-protected storage container.
Local File Access Only: Vault files never leave your physical device and do not sync to any cloud service. The feature utilizes Android's standard FileProvider mechanism for secure local file access only.
Currency Converter
The Currency Converter feature fetches public exchange rate data from the Frankfurter public API (api.frankfurter.dev).
Only anonymous currency codes (such as USD, EUR, INR) are transmitted to fetch rates. No personal data or user identifiers are included in exchange rate requests.
Advertising (Google AdMob)
SimpleCalculator integrates Google AdMob to display advertisements, including banner, interstitial, rewarded, and app-open ads.
Google AdMob may collect and process device advertising IDs, IP addresses, and diagnostic data for ad delivery, measurement, and personalization according to Google's Privacy Policy.
Rewarded Advertisements: Rewarded video ads are used to unlock additional AI solution generations beyond the initial free usage limit (3 free uses) and to unlock reference learning links.
Permissions Used
- CAMERA Permission: Requested solely for capturing math problems for the AI camera scanner feature.
- INTERNET Permission: Required for serving Google AdMob advertisements, sending extracted problem text to the NVIDIA AI API, and fetching currency rates from api.frankfurter.dev.
- No Sensitive Permissions: The App does NOT request or use location, contacts, microphone, SMS, or phone state permissions.
Data Storage & Data Deletion
All user data (calculation history, app preferences, vault files, and AI usage counters) is stored locally on your device using Android's standard SharedPreferences and app-private directory storage.
Permanent Data Deletion: Uninstalling SimpleCalculator permanently erases all locally stored data, history, and vault files from your device.
Children's Privacy
SimpleCalculator is a general-audience utility application. It is not directed at children under the age of 13.
We do not knowingly collect personal information from children under 13. AdMob ad requests are configured in accordance with Google Play developer policies and applicable privacy laws.
Changes to This Privacy Policy
We may update this Privacy Policy from time to time to reflect changes in app functionality, regulatory requirements, or third-party services. Any updates will be published on this page with a revised effective date.
Contact Us
If you have any questions or concerns regarding this Privacy Policy or SimpleCalculator, please contact us at:
Email: support@katrex.in
Developer Name: Katrex Technologies
Location: Balaghat, Madhya Pradesh, India