Privacy Policy

Effective October 10, 2026

This policy explains what information the Vocabulary app for iPhone (listed on the App Store as “Vocabulary - Daily English”) collects, why, and what choices you have. Vocabulary is published by San Thu Gao (“we”, “us”).

In short: you can use Vocabulary without an account; we create a random anonymous ID so your progress, streak and Pro access are saved. If you choose to sign in with Apple, Google or email, we store that sign-in so your progress comes back on another device. We use usage analytics (you can turn them off in Profile) and crash reports to improve the app. We don’t sell your data. The free version may show ads; Pro never does. Only if you allow tracking when the app asks, we use your device’s advertising identifier to see which of our ads brought you to the app. You can delete your account and data in the app at any time.

What we collect

Data	Why	Processed by
A random anonymous user ID created on first launch; if you sign in, your email address and (with Sign in with Apple, only if you share it) your name	To save your progress and Pro access, and to restore them on another device	Google Firebase Authentication
Your learning profile and progress: translation language, learning goal, level, topics, daily goal, reminder time, accent, theme and widget style; words seen, saved and mastered; quiz answers; streak, XP and daily activity; time zone and app language	To pick your daily words, schedule reviews, show your stats and keep your settings	Google Cloud Firestore
A push notification token	To send one optional reminder before your streak ends	Firebase Cloud Messaging, Apple Push Notification service
Purchase history (product, dates, price, country)	To unlock Pro, restore purchases and keep earlier subscriptions working	RevenueCat, Apple
Usage events (for example screens opened, words learned, quizzes completed, purchase started), device model, iOS version, app version, language and approximate country derived from the IP address	To understand which features people use and improve the app	Amplitude, Google Analytics for Firebase
App installs and opens, finishing onboarding, opening the Pro screen and purchases, with a random app ID, device model, iOS version and IP address	To measure how our ads on Facebook and Instagram perform	Meta (through the Meta SDK and RevenueCat)
The usage events above, including app installs, finishing onboarding and purchases, with the Google Analytics app instance ID	To measure how our ads on Google (Search, YouTube, Google Play and partner apps) perform	Google Ads (through Google Analytics for Firebase)
Free version only: ads shown and tapped, device model, iOS version, IP address and a random app ID; your consent choices where the law requires them	To show an ad when you return to the app, and to measure and limit those ads	Google AdMob
Only if you allow tracking: your device’s advertising identifier (IDFA), together with the vendor identifier and IP address, attached to the usage events and purchase records above	To measure which of our ads bring new learners and purchases	Amplitude, RevenueCat, Meta, Google (including AdMob)
Crash reports and diagnostics	To find and fix bugs	Firebase Crashlytics

We do not collect your contacts, precise location or photos.

Tracking and ads

The free version of Vocabulary may show a full-screen ad from Google AdMob when you come back to the app; Pro never shows ads. In the European Economic Area and the UK, the app first asks for your consent to Google’s use of your data for ads, and you can change it any time in Profile → Ad privacy choices. We also advertise the app on other services, and to learn which of those ads bring new learners, the app asks once for permission to track (Apple’s App Tracking Transparency). If you allow it, the advertising identifier is added to the usage events and purchase records described above, so they can be matched with the ad that led to your install. If you don’t, the identifier is never collected and the app works exactly the same; Meta then only receives the events above without it, which it reports to us in aggregate (Aggregated Event Measurement), and Google receives them without advertising consent, so it can use them only for aggregated, modeled ad measurement. You can change your choice at any time in iOS Settings → Privacy & Security → Tracking. To report an inappropriate ad, use Profile → Report an ad.

Microphone and speech

“Say it aloud” uses the microphone only while you hold the mic button, and Apple’s speech recognition turns what you said into text to check your pronunciation. Recognition runs on your device when your iPhone supports it; otherwise Apple processes it under Apple’s privacy policy. We never receive or store your voice recordings.

Reminders and widgets

Daily reminders are scheduled on your device at the time you pick. Widgets read today’s word, your streak and your daily goal from storage shared with the app on your device. Share cards you save are added to your photo library only with your permission; the app cannot read your library.

Payments

Payments are handled by Apple. We never receive your card or bank details. RevenueCat receives the purchase records Apple provides so that Pro can be unlocked and restored.

Sharing

We share data only with the service providers listed above, who process it on our behalf, and when required by law. Each provider may use the data only to provide its service to us. We do not sell or rent personal data. We use it for advertising only to measure our own ads and, in the free version, for the AdMob ads described under “Tracking and ads”.

Google Firebase: firebase.google.com/support/privacy
Amplitude: amplitude.com/privacy
RevenueCat: revenuecat.com/privacy
Google Ads and AdMob: policies.google.com/privacy (how Google uses data from partner apps)
Meta: facebook.com/privacy/policy

These providers may process data in the United States and other countries.

How long we keep it

We keep your account, learning progress and purchase history for as long as you use the app. Analytics events are kept for up to 14 months in Google Analytics and for the retention period configured in Amplitude. Crash reports are kept for 90 days.

Deleting your data and your rights

You can delete your account and all learning data at any time in the app under Profile → Delete account. You can turn off usage analytics at any time in Profile → Share usage data: the app then stops sending events to Amplitude, Google Analytics and Meta. Depending on where you live (for example under the GDPR or the CCPA), you can also ask us to access, correct or delete your data, or object to its processing, by emailing santhugao@gmail.com. Deleting the app does not cancel a subscription, which you manage in your Apple ID settings.

Children

Vocabulary is not directed to children under 13, and we do not knowingly collect personal information from them. If you believe a child has used the app, contact us and we will delete the related data.

Changes

We will post any changes on this page and update the effective date. Significant changes will also be announced in the app.

Contact

San Thu Gao · santhugao@gmail.com