Privacy policy

Last updated 2 November 2026

This policy covers the exam practice apps that Mathtify (VIETNAM OPEN SOURCE TECHNOLOGY COMPANY LIMITED) publishes on the App Store and Google Play, and this website.

• There is no account and no sign-in. We do not collect or store personal data on our servers.
• Your progress stays on your phone.
• Question banks you haven't unlocked show ads from Google AdMob, which collects device identifiers and advertising data.

What stays on your phone

Your answers, progress, bookmarks and settings are stored only on your phone. On first launch the app creates a random install ID and keeps it in the phone's secure storage (the iOS Keychain or Android encrypted storage). It is not linked to your name, email or phone number, and it is not sent to us. Uninstalling the app deletes your progress; on iOS the install ID can remain in the Keychain.

Downloading question banks

The app downloads question banks from mathtify.com, which Cloudflare hosts. Like any web request, these downloads carry your IP address and basic device information. We do not use them to identify you, and the app sends nothing else with them.

Purchases

Purchases are made through the Apple App Store or Google Play and are covered by their privacy policies. We never receive your name or payment details. The app checks what you have bought on the phone, from the store's records; "Restore purchases" uses the same records.

Advertising

Until you unlock a question bank, the app shows ads from Google AdMob in it. To show and measure ads and to prevent fraud, Google's AdMob SDK collects data such as your device's advertising identifier, IP address and how you interact with ads, and it may show personalised ads.

• In the European Economic Area, the United Kingdom, Switzerland and wherever else the law requires it, the app first asks for your consent with Google's consent message, and you can change your choice later in the app.
• On iOS, the advertising identifier is available only if you allow tracking.
• On Android, you can reset the advertising identifier or opt out of personalised ads in your device settings.

Google explains how it uses this data at policies.google.com/technologies/partner-sites. Unlocking a question bank removes its ads.

Children

Our apps are not directed at children, and we do not knowingly collect data from children.

Selling and sharing

We do not sell personal data, and we hold none. The only data that leaves the app for a third party is what Google's AdMob SDK collects, described above.

Your choices

Because we hold no personal data about you, there is nothing for us to access, correct or delete. To delete your progress, uninstall the app. For advertising data, use your device settings or contact Google.

Changes

We will post any change to this policy on this page and update the date above.

Contact

Mathtify (VIETNAM OPEN SOURCE TECHNOLOGY COMPANY LIMITED), support@mathtify.com