FlexLex Last Updated: April 5, 2026
This Privacy Policy describes how FlexLex (“the App”, “we”, “us”, or “our”) handles information when you use our mobile application. By using the App, you agree to the practices described in this Privacy Policy. If you do not agree, please do not use the App.
FlexLex is a vocabulary learning application designed with a privacy-first approach. The App operates primarily offline. We do not collect, store, transmit, or sell your personal data to any server, third party, or advertising network. All learning data you create stays on your device unless you choose to export or share it.
All data created within the App is stored locally on your device in a private application directory. This includes:
This data is not encrypted by the App beyond the default filesystem encryption provided by your device’s operating system. If your device is compromised, this data could be accessible. We recommend keeping your device secured with a screen lock.
The App requests camera and photo library permissions solely for the following purposes:
You may deny these permissions; the App will continue to function without camera or photo features.
The App is designed to work offline. However, certain optional features require an internet connection. These features are always user-initiated and never occur in the background without your action.
When you first use spell-check for a given language, the App downloads open-source Hunspell dictionary files from GitHub (raw.githubusercontent.com). These files are cached locally for offline use. No personal data is sent during this download.
The App provides optional translation suggestions using on-device machine learning. The technology used depends on your platform:
Android: The App uses Google ML Kit for on-device translation. When you download a translation model for a language, the model files (approximately 30 MB each) are downloaded from Google’s servers. After download, all translations are performed entirely on your device. No text you translate is sent to Google or any external server. Google ML Kit SDKs may automatically collect device and app information, performance metrics, and diagnostic data for Google’s internal analytics and product improvement purposes, even when translation is performed on-device. This data collection is governed by Google’s Privacy Policy and is not controlled by us. For details on what ML Kit collects, see Google’s ML Kit data disclosure documentation.
iOS: The App uses Apple’s built-in Translation framework (available on iOS 18.0 and later) for on-device translation. All translations are processed entirely on your device using Apple’s system translation models. No text you translate is sent to any external server by the App. The Translation framework is provided and managed by Apple as part of iOS. For details on how Apple handles data, see Apple’s Privacy Policy.
The set of supported translation languages may differ between platforms, as each relies on its respective provider’s available language models. Translation suggestions are provided as a convenience and may not be available for all language pairs on all devices.
The App uses your device’s built-in text-to-speech (TTS) engine to pronounce words. Depending on your device and OS configuration, the TTS engine may use cloud services provided by your device manufacturer (e.g., Google, Apple). We do not control or have access to any data processed by your device’s TTS service.
The App allows you to export your study sets and create full backups of your data. Exported files are saved in standard formats (.json, .zip) and shared via your device’s native share sheet. Once you share or save a backup file, the security of that file is your responsibility. Backup files are not encrypted by the App.
We strongly recommend storing backups in a secure location and not sharing them publicly, as they contain your complete study data.
We do not share, sell, rent, trade, or otherwise disclose any of your data to any third party. The only way your data leaves your device is if you:
The App does not knowingly collect any personal information from anyone, including children under the age of 13 (or the applicable age of digital consent in your jurisdiction). Since the App does not collect personal information, it does not require parental consent under the Children’s Online Privacy Protection Act (COPPA), the General Data Protection Regulation (GDPR), or similar legislation. However, children should use the App under parental supervision, particularly when using features that require internet access.
All your data is stored locally on your device. You have full control over it at all times.
We do not retain any data on external servers, so there is nothing for us to delete on our end.
While we take reasonable steps to ensure data integrity within the App, we cannot guarantee the absolute security of data stored on your device. Security depends on your device’s operating system, encryption settings, and physical security. We are not responsible for unauthorized access to your data resulting from device compromise, malware, or inadequate device security.
The App may interact with third-party services as described in Section 5. We are not responsible for the privacy practices, content, or security of any third-party services, websites, or platforms. We encourage you to review the privacy policies of any third-party services you interact with through the App.
The App processes all data locally on your device. No data is transferred across borders by the App. If you use optional features that connect to third-party services (Google, GitHub), those services may process data in accordance with their own privacy policies and applicable laws.
Since we do not collect or store any personal data, traditional data subject rights (access, rectification, erasure, portability) under regulations such as GDPR, CCPA, or similar laws are exercised directly on your device through the App’s built-in functionality (editing, deleting, exporting data).
We may update this Privacy Policy from time to time. Any changes will be reflected by updating the “Last Updated” date at the top of this document. We encourage you to review this Privacy Policy periodically. Your continued use of the App after changes constitutes acceptance of the updated policy.
THE APP IS PROVIDED ON AN “AS IS” AND “AS AVAILABLE” BASIS. WE MAKE NO WARRANTIES, EXPRESS OR IMPLIED, REGARDING THE ACCURACY, RELIABILITY, OR COMPLETENESS OF ANY TRANSLATIONS, OCR RESULTS, SPELL-CHECK SUGGESTIONS, OR OTHER CONTENT GENERATED BY THE APP OR THIRD-PARTY SERVICES USED WITHIN THE APP. USE OF THE APP AND ANY RELIANCE ON ITS OUTPUT IS AT YOUR OWN RISK.
If you have any questions, concerns, or requests regarding this Privacy Policy, please contact us at:
Email: privacy@flexlex.app
This Privacy Policy applies to the FlexLex mobile application distributed via the Google Play Store and/or Apple App Store.