Privacy Policy

Effective date: August 9, 2026

Last updated: October 24, 2026

1. Introduction

datila (“we”, “our”, “us”) is a mobile application for learning a new language from the very first words, explained in a language you already speak. It is available on Android and iOS and is intended for people aged 13 and older.

This policy explains what information the app collects, why, and what control you have over it. It applies to the datila mobile app and to datila.app.

Who is responsible for your data. The controller of the personal data described in this policy is Dương Quang Đăng, Đội 7, thôn Bích La Đông, Triệu Thành, Triệu Phong, Quảng Trị 520000, Vietnam. You can reach us at support@datila.app.

datila requires an internet connection. Lessons, images, and audio are downloaded from our content servers as you use the app.

2. Your voice recordings never leave your device

3. Information we collect

Account information

• An anonymous account is created automatically the first time you open the app, so your progress can be saved before you decide whether to sign in. It contains no personal information.
• Sign-in with Google or Apple is required to continue beyond the first lesson (or the first 50 questions in Challenge) and to make a purchase. When you sign in, we receive the account identifier and email address that the provider supplies. We never see or handle your password. If you use Apple’s “Hide My Email”, we only ever see the relay address.

Device and installation identifiers

• An installation ID — a random identifier the app generates on your device the first time it runs. It is not a hardware identifier, is not shared with other apps, is excluded from cloud backup and device transfer, and a new one is generated if you reinstall the app or delete your account. Because a new one is generated on deletion, activity after you delete your account is not linked to anything you did before it.
• Basic device and app information — app version, operating system version, device model, and language settings, used for compatibility and diagnostics.

Learning data

• Which languages you are learning, which lessons you have completed, your review schedule, and your app settings. This is stored on your device and synchronised to your account so it survives changing or resetting your phone.
• In Challenge — a quiz mode for people who already know some of the language, available for some language pairs — the app keeps an estimate of your level and the questions you have seen recently, so that it can pick questions that suit you. This stays on your device and is not saved to your account.

Challenge points and the weekly leaderboard

• Points. Before you sign in, your Challenge points stay on your device. Once you sign in with Google or Apple, your total and your points for recent weeks are saved to your account, together with a random code the app creates for each device you play on, so that your total adds up across devices and survives a new phone.
• The weekly leaderboard is optional and you appear on it only if you choose to join. Other signed-in datila users who open the leaderboard for the same language can then see one row for you each week: a nickname the app picks at random (never your real name or email), your level, your points that week, the time your points last went up, and the language you speak, which is used to group the board. Your account ID and email address are never shown.
• You can switch to another random nickname at any time in Settings → Nickname. Turning off Settings → Show me on the leaderboard removes your rows from every week’s board straight away; your points are kept.
• We may hide a leaderboard row that looks abnormal. The leaderboard has no prizes.

Usage and diagnostics

• Analytics events describing how the app is used — for example that a lesson was started or finished, or that a download failed. These are tied to the installation ID, not to your name or email.
• Campaign measurement — when we run advertising campaigns to find new learners, AppsFlyer tells us which campaign, if any, led to an installation. It receives the installation ID described above (never your account ID, name, or email), basic device and network information including your IP address, and five milestone events: choosing your languages, your first correct answer in a session, completing a lesson, opening the purchase screen, and completing a purchase (with its price and currency). AppsFlyer may report these events, without your name or email, to the advertising platform that ran the campaign, such as Meta, so that platform can measure it. Where your device makes an advertising identifier available to apps, AppsFlyer may receive it too; on iOS it never does, because datila does not ask for tracking permission. In the European Economic Area, the United Kingdom, and Switzerland this does not start until you consent (see section 9).
• Crash reports containing the state of the app when it stopped unexpectedly.
• Network information — our content delivery network sees your IP address when the app downloads lessons, images, and audio, as any web request does.

Explanations inside stories

When you tap a word in a story, or tap Explain this sentence, the app asks our server to explain that sentence. If no learner has asked about it before, our server writes the explanation with an AI service. The AI service receives only the text of the lesson and the two languages involved — never your account, your device details, or anything else that identifies you. The explanation is then stored on our server and shown to every learner who asks about the same sentence; it is not linked to you.

Feedback you send us

Settings → Send feedback lets you write to the datila team. Nothing is sent unless you press Send, and only what you choose:

• Your message and the topic you pick (a problem, an idea, words or translation, or something else).
• A screenshot, only if you add one. You pick it yourself in your phone’s own photo picker; the app never sees the rest of your photos. Before it leaves your device the picture is made smaller and all of its hidden metadata (EXIF) is removed, including any location where it was taken.
• Your email address, only if you enter one, so that we can reply. It is used for nothing else.
• Technical details, if you leave that switch on (it is on by default, and you can turn it off before sending): app version, operating system, the course you are learning, the app’s display language, and a support code — your account’s internal ID — so that we can find your account if you ask for help with it.

Your message is delivered by email to our support mailbox. Our own servers do not keep a copy; the email delivery service listed in section 10 keeps a delivery record under its own policy. To prevent abuse, your account keeps only a count of how many messages it has sent today. That count contains no content and is deleted together with your account.

Report this question in Challenge uses the same delivery, but sends only which question it was, its version, and the reason you picked. It does not include your email address, a screenshot, technical details, or your support code.

What we do not collect

Voice recordings (see section 2), precise location, contacts, photos (other than a screenshot you choose to attach to feedback, see above), files, browsing history, biometric data, health data, or payment card details. We do not use advertising identifiers for cross-app tracking, and the app does not ask for App Tracking Transparency permission on iOS because it does not track you across other apps or websites.

4. Permissions the app asks for

5. Advertising

datila is free to use and shows advertisements to free users. Ads are served by Google AdMob.

We serve non-personalized ads only. Ads are chosen from general context rather than from a profile of you, and we do not track you across other apps or websites for advertising purposes.

Where ads appear is limited by design, not by configuration. There are no ads:

• before your first completed lesson — in Challenge, before your first 50 questions on a device;
• in the first lesson of a language, ever;
• during a lesson, or right after a wrong answer;
• while a Challenge question or its explanation is on screen;
• before an explanation opens;
• in a session you opened from a review reminder.

In Challenge, an ad can appear only at a break between rounds of questions, where you are offered a short ad to keep playing. If you reach a new level during a round, that round’s break has no ad.

If you are in the European Economic Area, the United Kingdom, or Switzerland, the app asks for your consent for ad-related identifiers and measurement through Google’s User Messaging Platform before any such data is used, and records your choice. You can review or change that choice at any time from Settings → Privacy options in the app.

If you do not consent, the app still works in full and you can still learn every lesson. Ads may still be shown, but without access to identifiers or on-device storage, which generally means fewer and less relevant ads.

Ad networks may process limited signals such as device type and the approximate region inferred from your IP address in order to deliver and measure ads and to detect fraud, under their own privacy policies. We do not sell your personal data, and we do not share it for cross-context behavioural advertising.

6. Purchases

You can remove ads from a language — in lessons, games, and Challenge — with its ad-free plan, a yearly subscription that renews automatically until you cancel it in your Google Play or App Store account. Each language has its own plan — subscribing for English does not remove ads from Japanese. This is stated on the purchase screen before you buy, not after.

All payments are handled entirely by the Google Play Store or the Apple App Store. We never see or store your card details, billing address, or any financial information. We use RevenueCat to verify with the stores which purchases your account holds; RevenueCat receives your account identifier and the purchase receipt issued by the store.

7. Notifications

If you allow notifications, we send two kinds: a reminder when words you have learned are due for review, and occasional reminders to come back if you have stopped using the app. You can turn them off at any time in your device settings or in the app.

8. How we use your information, and on what legal basis

If you are in the European Economic Area, the United Kingdom, or Switzerland, we must tell you the legal basis on which we process your data. This is that list.

We do not sell your personal data, and we do not share your learning data with advertisers.

9. Analytics and your consent

Analytics collection is switched off by default when the app starts. In the European Economic Area, the United Kingdom, and Switzerland, no analytics event is recorded or sent unless you have given consent, and events that occurred before you consented are discarded rather than sent later. If you withdraw consent, anything still waiting to be sent is deleted and is never sent afterwards. The same applies to campaign measurement by AppsFlyer (section 3): in those regions it does not start until you consent, and it stops as soon as you withdraw consent in Settings → Privacy options.

Outside those regions, analytics events are collected as described in section 3 without a separate consent prompt, and you can still ask us to delete your data as described in section 11.

10. Third-party services

11. Your choices, your rights, and how to delete your data

What you can do in the app

• turn review reminders off, in the app or in your device settings;
• review or withdraw your advertising and analytics consent, where consent applies, from Settings → Privacy options;
• send us feedback from Settings → Send feedback, and choose whether to include a screenshot, your email address, and technical details;
• leave the Challenge leaderboard from Settings → Show me on the leaderboard, or switch to another random nickname from Settings → Nickname;
• uninstall the app, which removes everything stored on the device.

Deleting your account

Your rights

Depending on where you live, you have rights to access, correct, export, delete, or restrict the use of your personal data, to object to certain processing, and to withdraw consent at any time — for example under the GDPR, the UK GDPR, the Swiss FADP, or the CCPA/CPRA. Withdrawing consent does not affect processing that already happened while consent was in place.

Write to support@datila.app and we will respond to verified requests within one month. We will not treat you differently for exercising any of these rights.

If you are in the European Economic Area, the United Kingdom, or Switzerland and you think we have handled your data wrongly, you also have the right to lodge a complaint with your national data protection authority. You do not have to contact us first, though we would rather you did.

12. How long we keep things

13. Children’s privacy

datila is intended for people aged 13 and older, and is not directed at children. We do not knowingly collect personal information from children under 13, or under the age of digital consent where that age is higher. If you believe a child has provided us with personal information, write to us and we will delete it promptly.

14. International transfers

The services listed in section 10 operate globally, so your data may be processed outside the country you live in, including in the United States. Where data leaves the European Economic Area, the United Kingdom, or Switzerland, these transfers rely on the European Commission’s Standard Contractual Clauses, on the EU–US Data Privacy Framework and its UK and Swiss extensions where the provider is certified, or on an adequacy decision — as set out in each provider’s own privacy documentation linked in section 10.

15. Changes to this policy

We may update this policy. When we do, the “last updated” date at the top changes, and significant changes are announced in the app. Continuing to use datila after a change means you accept the updated policy.

16. Contact

Dương Quang Đăng
Đội 7, thôn Bích La Đông, Triệu Thành, Triệu Phong, Quảng Trị 520000, Vietnam
Email: support@datila.app
Website: https://datila.app