Privacy Policy
Last updated: June 25, 2026
This Privacy Policy explains how the CDL Prep mobile app ("the App", "we", "us"), operated by MD Teknoloji, handles information when you use it. We built CDL Prep to work without an account, and we do not sell your data or use it for advertising.
The short version. You don't create an account. We don't ask for your name, email, or phone number. We don't track you across other apps, and there are no ads. Your study progress stays on your device. We use a small amount of anonymous usage and crash data to keep the App working, and a few well-known services to deliver the App, process subscriptions, and translate content.
1. Information we process
Information you provide in the App
- Preferences — the U.S. state you select, your interface and native language, theme (light/dark), and daily reminder time. These are stored on your device.
- Study activity — your quiz answers, scores, and review progress, used to track your learning and power spaced-repetition review. Stored on your device.
- Translation requests — when you tap to translate a question or explanation, the text of that item and your chosen language are sent to our backend and to our translation provider to generate the translation (see Section 4).
Information collected automatically
- An anonymous app identifier — a random ID that the App generates and stores on your device. It is not your device's hardware identifier and is not an advertising identifier. It lets us count usage and link a subscription to your install without knowing who you are.
- App and device technical data — app version, platform (iOS/Android), operating-system version, device model, and language, used for analytics and to diagnose problems.
- Usage events — anonymous, aggregate-style events such as screens viewed, a quiz started, the paywall being shown, or a reminder being toggled, used to understand how the App is used and improve it.
- Crash and diagnostic data — error reports and stack traces when the App crashes or misbehaves.
What we do not collect
- Your name, email address, or phone number.
- Your precise or background location. (You choose a U.S. state manually; the App does not read GPS.)
- Your contacts, photos, microphone, or camera.
- Advertising identifiers (IDFA/AAID). The App shows no ads and does not use App Tracking Transparency tracking.
- Payment card details — these are handled entirely by Apple and Google (see Section 3).
2. How we use information
- To provide the core features: quizzes, exam simulation, progress tracking, and reminders.
- To process and restore your CDL Pro subscription.
- To translate study content into your preferred language.
- To diagnose crashes and fix bugs.
- To understand aggregate usage so we can improve the App.
We rely on our legitimate interest in operating and improving the App, on performing our agreement with you (subscriptions), and — where required — on your device-level permissions (such as notifications).
3. Subscriptions and payments
CDL Prep offers an optional auto-renewable subscription ("CDL Pro"). All payments are processed by Apple App Store or Google Play under their own terms and privacy policies. We never receive or store your payment card information.
We use RevenueCat to manage subscription status and to restore purchases. RevenueCat receives your anonymous app identifier, the platform, and the purchase receipt provided by Apple/Google so it can tell the App whether your subscription is active.
4. Translation feature
When you ask the App to translate a question or explanation, the text of that item and your target language are sent over a secured connection to our backend (api.denapp.xyz), which uses OpenAI to generate the translation. The result is cached on your device and on our servers so the same content does not need to be translated again. The text translated is the App's study content; the feature is not intended for entering personal or sensitive information.
5. Service providers we share data with
We do not sell your information. We share the limited data described above with the following providers, only so they can perform their function. Each has its own privacy policy.
| Provider | Purpose | Privacy policy |
|---|
| Apple App Store / Google Play | Subscription billing & app distribution | apple · google |
| RevenueCat | Subscription management & restore | revenuecat.com |
| Mixpanel | Anonymous product analytics | mixpanel.com |
| Sentry | Crash & error reporting | sentry.io |
| Expo (EAS) | App delivery & over-the-air updates | expo.dev |
| OpenAI | Translation of content you request | openai.com |
Our own backend (api.denapp.xyz) stores the anonymous guest record used to run the translation feature and link your subscription. Connections to our backend are protected with TLS and certificate (public-key) pinning.
6. Notifications
If you enable the daily study reminder, the App schedules a local notification on your device at the time you choose. This requires the operating-system notification permission, which you can revoke at any time in your device settings. The reminder is generated on your device; we do not send it from a server.
7. Data retention and storage
- On-device data (preferences, study progress, translation cache, the anonymous identifier) remains on your device and is removed when you uninstall the App.
- Server-side data (the anonymous guest record and cached translations) is retained while it is needed to operate the App and may be deleted on request (see Section 9).
- Analytics and crash data are retained by the respective providers according to their policies.
8. Children's privacy
CDL Prep is intended for adults preparing for a U.S. Commercial Driver's License, who must meet the minimum age set by their state (generally 18 or 21). The App is not directed to children under 13, and we do not knowingly collect personal information from children.
9. Your choices and rights
- Delete your data — uninstalling the App removes all on-device data. To request deletion of the anonymous guest record and cached translations on our servers, contact us (Section 12).
- Notifications — turn the reminder off in the App, or disable notifications for CDL Prep in your device settings.
- Subscriptions — manage or cancel anytime in your Apple ID or Google Play account settings.
- Regional rights — depending on where you live (e.g., the EEA/UK under GDPR, or California under the CCPA/CPRA), you may have rights to access, correct, or delete your data. Because most of what we hold is anonymous, we may ask for your app identifier to act on a request.
10. International transfers
Our providers may process data in the United States and other countries. Where required, transfers rely on appropriate safeguards such as the providers' standard contractual clauses.
11. Changes to this policy
We may update this Privacy Policy from time to time. We will revise the "Last updated" date above, and significant changes will be reflected in the App or its store listing.
12. Contact us
Questions or requests about this policy or your data: support@denapp.xyz (MD Teknoloji).
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