Last updated: March 8, 2026 · Effective: March 8, 2026
Summary for Mathix: This app requires no sign-up, no account, and no personal information. All your data is stored locally on your device. The only network request the app makes is a one-time font download from Google Fonts. We do not track you, profile you, or sell any data.
Mathix ("the App") is developed and published by Kelthos ("we," "us," or "our"). Mathix is part of the Kelthos suite of privacy-first utility applications.
Mathix is a Scientific Calculator application. It is designed as a utility tool that works instantly without requiring any user registration, login, email verification, or personal information of any kind.
We do not collect, store, process, or transmit any personally identifiable information (PII).
Specifically, Mathix does NOT collect:
Mathix stores the following data exclusively on your device using the Android SharedPreferences API (a standard, sandboxed, local key-value store):
Purpose: Store your calculation history and memory values for reference.
Settings → Apps → Mathix → Storage → Clear DataAndroid may include Mathix's local data in your device's automatic backup (Google Drive backup) if you have enabled this feature in your device Settings. This backup is governed by Google's Privacy Policy, not ours. You can disable auto-backup for this app in your device settings.
Mathix does not request any special device permissions beyond basic app functionality. The app operates entirely within its own sandboxed storage on your device.
We believe in full transparency about every piece of software that runs within our app. Below is a complete and exhaustive list of all third-party components, what they do, and what data (if any) they access.
| Provider | Google LLC |
| Purpose | App distribution, updates, and installation |
| Data collected by Google | Google may collect device identifiers, app install/uninstall events, crash reports (if enabled by you in device settings), and usage statistics as part of their Google Play Services. This data collection is governed entirely by Google's Privacy Policy and is outside our control. |
| Data we receive | We may receive aggregated, anonymized statistics through the Google Play Console (e.g., total installs by country, crash rates, Android version distribution). We do not receive any personally identifiable information. |
| Privacy Policy | https://policies.google.com/privacy |
| Provider | Google LLC |
| Purpose | Download the "Inter" font family used throughout the app's user interface. This is a one-time download per device — the font is cached locally after first retrieval. |
| Network requests | On first app launch (or after cache is cleared), the app makes HTTPS requests to fonts.googleapis.com and fonts.gstatic.com to download font files. |
| Data transmitted to Google | When the font is fetched, the following information is transmitted to Google's servers: • Your device's IP address • The font name requested ("Inter") • Standard HTTP headers (User-Agent, which may include your device model and Android version) Google states that font API requests are not logged or stored alongside other authenticated Google services. See Google's Google Fonts Privacy FAQ. |
| Data retention by Google | According to Google: CSS font requests are cached by the browser/device and are not logged. Font file requests are cached for 1 year to improve performance. |
| Privacy Policy | https://policies.google.com/privacy Google Fonts Privacy FAQ |
| Provider | Google LLC (open-source) |
| Purpose | Cross-platform application framework used to build this app |
| Network requests | None. Flutter itself does not make any network requests or phone home. It is compiled into native code. |
| Source code | https://github.com/flutter/flutter (BSD-3 license) |
| Package | flutter_riverpod v2.6.1 |
| Purpose | In-app state management — manages how data flows within the app |
| Network requests | None. Pure Dart code running entirely on your device. |
| Source | pub.dev/packages/flutter_riverpod |
| Package | shared_preferences v2.3.4 |
| Purpose | Stores app settings and data as key-value pairs in the device's local storage (Android SharedPreferences / iOS NSUserDefaults) |
| Network requests | None. All data is stored exclusively on your device's local file system. |
| Source | pub.dev/packages/shared_preferences |
| Package | math_expressions v2.6.0 |
| Purpose | Parse and evaluate mathematical expressions (arithmetic, trigonometry, logarithms) |
| Network requests | None. Pure Dart mathematical computation on-device. |
| Source | pub.dev/packages/math_expressions |
| Provider | Kelthos (self-hosted via Cloudflare R2) |
| Purpose | An optional, opt-in feature that may be introduced in a future update to allow you to sync app data across multiple devices |
| Current status | Not yet active. If/when enabled, it will be strictly opt-in and never activated without your explicit consent. |
| How it will work | If you choose to enable cloud sync, your app data will be encrypted and uploaded to our servers via sync.kelthos.com. Data is stored on Cloudflare R2 (part of Cloudflare's global network). Your device ID will be hashed (SHA-256) before storage — we will never store your raw device identifier. |
| Data stored | Only the specific app data you choose to sync (notes, settings, preferences). No personal information, no analytics, no usage tracking. |
| Data deletion | You will be able to delete all synced data at any time through the app's settings. |
| Infrastructure | Cloudflare R2 (Western Europe region). Subject to Cloudflare's Privacy Policy. |
| This policy will be updated | Before any cloud sync feature is released, this Privacy Policy will be updated with specific details about what data is synced, how it is encrypted, and how to delete it. |
The list above represents the complete and exhaustive inventory of all third-party code included in this app. We do not use any advertising SDKs, analytics SDKs, social media SDKs, crash reporting SDKs, A/B testing SDKs, attribution SDKs, or any other tracking technology not listed above.
Specifically, this app does NOT include:
For complete transparency, here is every network request Mathix makes:
| When | Destination | What's Sent | Purpose |
|---|---|---|---|
| First launch (one-time) | fonts.googleapis.comfonts.gstatic.com |
Font name ("Inter"), your IP address, HTTP User-Agent header | Download the Inter font for the app's UI |
| That's it. No other network requests are made. The app functions fully offline after the initial font download. | |||
We do not share, sell, rent, or trade any user data with any third party. Period.
The only data that leaves your device is:
Since all data is stored locally on your device:
Because we do not collect, transmit, or store your data on any server:
Mathix does not collect personal information from any user of any age, including children under 13 (as defined by COPPA — Children's Online Privacy Protection Act) or under 16 (as defined by GDPR).
Because no personal data is collected, no parental consent mechanism is needed. The app is safe for users of all ages.
If you are located in the European Economic Area (EEA), United Kingdom, or Switzerland, you have the following rights under the General Data Protection Regulation (GDPR):
Legal Basis for Processing (Art. 6): The minimal data processing that occurs (local storage on your device) is based on legitimate interest — the app cannot function without storing your settings and content locally. The Google Fonts network request is based on legitimate interest in providing a consistent, accessible user interface.
Data Protection Inquiries: Contact legal@kelthos.com
If you are a California resident, the California Consumer Privacy Act (CCPA) provides you with specific rights. Because we do not collect personal information:
Since we do not collect or transmit personal data to servers, there are no international data transfers by our app. The Google Fonts request (Section 6.2) may be routed to Google servers globally, which is governed by Google's own data processing practices and their Privacy Policy.
In accordance with Google Play's Data Safety requirements, here is our declaration for Mathix:
| Data shared with third parties | No data is shared with third parties |
| Data collected | No user data is collected |
| Data encrypted in transit | Yes (HTTPS for Google Fonts request) |
| Users can request data deletion | Yes (clear app data or uninstall) |
| Committed to Play Families Policy | The app does not collect data from users of any age |
We may update this Privacy Policy from time to time. When we do:
If you have any questions, concerns, or requests regarding this Privacy Policy or Mathix's data practices, please contact us:
Our Privacy Commitment: Mathix is built on a simple principle — your tools should work for you, not spy on you. No accounts, no tracking, no data harvesting, no ads. Just a useful app that respects your privacy completely.