Privacy Policy

Lumo Browser ("the App", "we", "us", "our"), operated by Tranquil Mind Technology JSC, respects your privacy. This Privacy Policy explains what information we collect, how we use and share it, and the choices and rights you have. By using the App, you agree to this Policy.

Lumo Browser is a mobile web browser: it lets you open and manage multiple tabs, reach popular sites through one-tap shortcuts, block web advertising, trackers and pop-ups with a built-in blocker, see how long protection has been running and how much it has blocked, choose from 25 interface languages, and optionally subscribe to Premium to remove in-app advertising. You do not need to create an account, sign in, or provide any personal details to use Lumo Browser — there is no login, no profile, no messaging, and no user-to-user content.

1. Information we collect

We do not ask you for your name, email address, phone number, contacts, photos, files, or precise location. The App has no registration form and no user account.

The following information is collected automatically by the App and the third-party services listed in Section 3:

1.1 Device and app information

Device model and manufacturer, operating system version, screen and language/region settings, app version and build, network connection type, and time zone. Used to operate the App, deliver the correct configuration, serve and measure advertising, and diagnose problems.

1.2 Identifiers

• Advertising ID (Google Advertising ID / GAID) — a resettable identifier provided by Android. It is used by the advertising, analytics and install-attribution services listed in Section 3; the App declares the com.google.android.gms.permission.AD_ID permission for that purpose.
• App-instance identifiers — Firebase installation ID / app instance ID used by Firebase Analytics, Crashlytics and Remote Config; an installation identifier used by Adjust for install attribution.
• Install referrer — the Google Play install referrer string, read through the BIND_GET_INSTALL_REFERRER_SERVICE permission, so we can tell which campaign or listing brought you to the App.
• Android Privacy Sandbox signals — the App includes advertising libraries that may use Android's Ad Services APIs (ACCESS_ADSERVICES_AD_ID, ACCESS_ADSERVICES_ATTRIBUTION, ACCESS_ADSERVICES_TOPICS, ACCESS_ADSERVICES_CUSTOM_AUDIENCE) where available on your device, under Google's Privacy Sandbox framework.

1.3 Approximate location (derived from IP address)

We do not request GPS or any location permission and the App does not access your device location. Our service providers may infer an approximate location (typically country or city level) from your IP address for advertising, analytics, fraud prevention and regional configuration.

1.4 App activity and diagnostics

Anonymous in-app events (for example: splash shown, language screen viewed, onboarding step completed, search bar tapped, ad-block toggled, settings row tapped, subscription screen viewed, share/rate/feedback tapped) and screen views. These events record that an action happened, together with the interest topic you optionally pick during onboarding. They do not contain the web addresses you visit, the pages you open, or the words you type into the search bar.

We also collect crash reports and diagnostic data (stack traces, exception messages, device state at the time of the crash, app version) through Firebase Crashlytics.

1.5 Advertising data

The free version of the App shows advertising (banner, native and full-screen formats) supplied by Google AdMob and its mediation partners. Those partners receive your advertising ID, IP address, device and app information, coarse location derived from your IP, and ad-interaction events (impressions, clicks) in order to select, display, cap and measure ads and to detect invalid traffic. See Sections 3.2 and 3.3.

1.6 Purchase and subscription information

The App uses Google Play Billing for optional Premium subscriptions. Google Play tells the App whether your Google account holds an active subscription to one of our products, and returns the localized price and offer details we display. We never see or store your payment card, billing address or Google account credentials.

When you start, complete or restore a purchase, the App also reports transaction metadata — the product identifier (for example lumo_premium_yearly), the price and the currency — to Adjust as a revenue event, and Adjust may relay that revenue signal to the advertising networks in Section 3.2 so they can measure the performance of marketing campaigns. This metadata identifies which product was bought and for how much; it contains no payment details and no identity information. See Sections 3.1 and 3.4.

1.7 Signals about apps installed on your device

The App does not request the QUERY_ALL_PACKAGES permission and does not read a full list of the apps you have installed. Its manifest declares a narrow <queries> element naming specific intents, so that Android can tell the App whether a suitable app exists for a given action: opening http/https links, opening mailto: and tel: links, the system share sheet, the Play Store (for the rating prompt), and detecting which app currently holds the default-browser role.

Separately, some of the advertising and attribution libraries bundled with the App may collect signals about apps present on your device for ad targeting, measurement and fraud prevention, under their own privacy policies. Because those libraries can transmit such signals off your device, we declare "Installed apps" in the Google Play Data safety section for this App. This category is declared because of those third-party libraries, not because Lumo itself inventories your apps.

1.8 Notifications

If you grant the notification permission, the App schedules local reminder notifications on your device (for example, to finish setting up the App). These are generated on the device by the App itself. There is no push-messaging service, no notification token, and nothing about notifications is sent to a server.

1.9 What we do not collect: your browsing

This is the most important point for a browser:

• Browsing history, open tabs, form input, cookies and site data stay on your device. They are handled by the Android WebView engine and stored in the App's private storage. We do not upload them, we do not back them up to our servers, and we have no server that could receive them.
• The App keeps no browsing history of its own. Tabs live only in the current session and are not written to disk; closing the App discards them.
• The App has no analytics event, log or crash field that records a URL, page title or search query.
• The built-in ad and tracker blocker runs entirely on your device. Its blocklist (~250 advertising and tracking domains derived from public EasyList/EasyPrivacy sources) is compiled into the App. No page you open is sent to us or to any blocklist server for checking.
• Clearing the App's data from Android Settings, or uninstalling the App, removes any locally stored browsing data.

1.10 Data the websites you visit receive

When you open a website in Lumo Browser, that website — like with any browser — receives your IP address, user-agent string and any cookies it has previously set, and may set new cookies. If you use the address bar to search, your query is sent to the search provider used by the App. This information is collected by those third parties under their privacy policies, not ours. See Section 11.

2. How we use information

• To provide and operate the App — render pages, keep your tabs for the session, apply your chosen language, apply the ad-block setting and keep its counters and protection timer.
• To show and measure advertising — deliver ads in the free version, cap how often they appear, measure impressions and clicks, and detect invalid traffic.
• To deliver configuration remotely — Firebase Remote Config lets us change App settings (such as ad placement and feature toggles) without shipping an update.
• To measure installs and campaign performance — attribution SDKs tell us which marketing source an install came from, and how much subscription revenue a campaign produced, in aggregate.
• To understand usage and improve the App — anonymous, aggregated event and screen analytics.
• To keep the App stable — crash and performance diagnostics.
• To sell, restore and manage Premium — confirm with Google Play whether you own an active subscription and remove advertising when you do.
• To send optional reminders — local re-engagement notifications, only if you granted notification permission.
• To comply with law — respond to lawful requests and enforce our Terms.

3. Third-party services

The App includes the following software development kits (SDKs). Each one is listed with the data it may receive.

3.1 Analytics, diagnostics, configuration and attribution — active

Adjust and the Meta SDK activate only when the corresponding measurement tokens are supplied through Firebase Remote Config; when no token is configured they perform no tracking.

3.2 Advertising — active in the free version

Advertising is served by Google AdMob. AdMob mediation may fill an ad request from any of the ad sources below, each of which is a separate controller of the data it receives.

Mediation ad sources deliver ads only when they are enabled and configured for the App in the AdMob console; when a network is not configured it receives no request and no data.

Personalised advertising and consent. Where the EU/UK, or another law requiring consent, applies, the App shows a Google User Messaging Platform (UMP) consent form before advertising is personalised, and passes your choice on to the advertising partners above. If you refuse, ads are limited to non-personalised advertising, which still uses your IP address and coarse device signals for frequency capping, fraud prevention and reporting. You can reopen the privacy options form from within the App where that option is available.

3.3 Advertising identifier controls

Resetting or deleting your advertising ID. On Android you can reset your advertising ID or delete it entirely at any time: Settings → Google → Ads → Reset advertising ID / Delete advertising ID, or Settings → Privacy → Ads depending on your device. Deleting it stops apps from receiving a personalised identifier.

Removing ads. Purchasing a Premium subscription removes advertising from the App; analytics, crash reporting and attribution continue as described above.

3.4 Purchases and store services — active

All payments are processed by Google Play — we never receive your payment details. As described in Section 1.6, the product identifier, price and currency of a completed purchase are also reported to Adjust as a revenue measurement event.

3.5 Services you reach through the App

We have no control over, and take no responsibility for, the data practices of these third parties.

4. How we share information

We do not sell your personal information for money, and we do not share your browsing history with anyone.

We share the limited data described above only:

• with the service providers in Section 3, for the purposes stated there — including the purchase metadata described in Section 1.6, which is shared with Adjust and, through Adjust, with the advertising networks in Section 3.2 for campaign measurement;
• when required by law, legal process, or a valid government request, or to protect our rights, safety, or property, or to investigate fraud or abuse;
• in a merger, acquisition, or asset sale, in which case we will post a notice of the change.

U.S. state privacy laws. We do not sell your personal information for money. However, when personalised advertising is enabled, the disclosure of your advertising ID and related device signals to the advertising partners listed in Section 3.2 may be treated as "sharing" for cross-context behavioural advertising, or as a "sale", under California and other U.S. state privacy laws. To opt out, decline personalised advertising in the consent form, delete or reset your advertising ID as described in Section 3.3, enable your device's "Opt out of Ads Personalisation" setting, or contact us at the address in Section 13.

5. Legal bases for processing (EEA / UK — GDPR)

• Consent — personalised advertising, and analytics and marketing measurement where local law requires consent; you may withdraw consent at any time.
• Legitimate interests — operating and securing the App, crash diagnostics, aggregated non-personalised analytics, frequency capping, preventing fraud and abuse.
• Performance of a contract — providing the App and fulfilling or restoring any subscription you purchase.
• Legal obligation — retaining records and responding to lawful requests.

6. Data retention

• Locally stored browsing data (cookies, cache, site data, your language, theme and ad-block preference, and the ad-block counters) stays on your device until you clear the App's data or uninstall it. Open tabs are held only for the current session. We hold no copy of any of it.
• Analytics and crash data are retained by Google for the periods set out in the Firebase documentation and our project settings (typically up to 14 months for event-level analytics data; crash records are retained for a limited diagnostic period).
• Advertising and attribution data, including purchase-revenue events, are retained by the partners in Sections 3.1 and 3.2 under our agreements with them and their own policies, generally for the period needed for ad delivery, billing and marketing measurement.
• Subscription records are held by Google Play under Google's own retention rules.
• We keep support correspondence only as long as needed to handle your request and to meet legal obligations.

7. Your rights and choices

7.1 In-app and on-device controls

• Clear your browsing data — clear the App's storage from Android Settings → Apps → Lumo Browser → Storage → Clear data, or uninstall the App.
• Reset or delete your advertising ID — see Section 3.3.
• Personalised advertising — decline or change your choice in the consent form shown by the App where applicable.
• Turn off notifications — Android Settings → Apps → Lumo Browser → Notifications, or decline the notification permission.
• Ad, tracker and pop-up blocking — the built-in blocker can be switched on or off in the App.
• Manage or cancel a subscription — Google Play → Profile → Payments & subscriptions → Subscriptions.

7.2 GDPR (EEA / UK)

You have the right to access, correct, delete, restrict, and port your personal data, to object to processing based on legitimate interests, to withdraw consent at any time, and to lodge a complaint with your local data protection authority.

7.3 CCPA / CPRA (California) and other U.S. states

You have the right to know what personal information is collected and how it is used and disclosed, to delete it, to correct it, to opt out of the sale or sharing of personal information and of targeted advertising, to limit the use of sensitive personal information, and not to be discriminated against for exercising these rights. We do not knowingly sell or share the personal information of consumers under 16 years of age.

7.4 Other regions

Residents of Brazil (LGPD), Canada (PIPEDA), and other jurisdictions with comparable laws have equivalent rights of access, correction, deletion, and objection.

7.5 How to exercise your rights, including deletion

Email us at contact@tranquilmind.co. Because the App has no user account, we cannot identify you from a name or email alone. Please include your Android advertising ID, your device model and the approximate date of installation so that we can locate any associated records with our advertising, analytics and attribution providers, and ask them to delete those records. We will respond within the period required by applicable law. Verification information is used only to process your request.

You can delete most of the data yourself and immediately: clearing the App's storage or uninstalling the App removes everything held on the device, and deleting your Android advertising ID severs the identifier that our advertising, analytics and attribution partners use.

8. Children's privacy

Lumo Browser is intended for users aged 16 and over (or the higher age of digital consent in your country). It is a general-audience utility and is not directed to children.

The App gives access to the open internet, and the pages you can reach are not created, filtered, or controlled by us. It has no content filter, no safe-search lock and no parental controls. Parents and guardians should supervise younger users and consider using Android's Family Link / parental controls and their search provider's safe-search settings.

We do not knowingly collect personal information from children under 13 (or under 16 in the EEA/UK, where a higher age applies). If you believe a child has provided personal information to us, contact contact@tranquilmind.co and we will delete it and any associated identifiers.

9. International data transfers

We are based in Vietnam and our service providers operate globally, including in the United States, the European Union, and Singapore. Your information may therefore be processed outside your country of residence, where data protection laws may differ. Where required, transfers rely on appropriate safeguards such as the European Commission's Standard Contractual Clauses or an adequacy decision.

10. Data security

All communication between the App and our service providers uses encryption in transit (HTTPS/TLS). Data stored by the App stays in Android's private, sandboxed app storage, protected by the operating system.

Note that the App allows plain-text (http://) connections so that legacy websites remain reachable, as browsers generally do. Traffic to such sites is not encrypted by the site itself; look for the padlock/https:// before entering sensitive information on any page.

Lumo Browser is not a VPN or proxy. It does not encrypt, tunnel or anonymise your network traffic beyond the encryption a website itself provides, and it does not hide your IP address from the sites you visit or from your network operator.

No method of transmission or storage is 100% secure, and we cannot guarantee absolute security.

11. Third-party content and websites

Lumo Browser is a gateway to the open web. We do not create, own, endorse, moderate, or control the websites, services, advertisements, or content you reach through it — including the sites behind the built-in shortcut tiles. Your use of any third-party website is governed by that site's own terms and privacy policy, and any data you submit there goes to that site, not to us. We are not responsible for third-party content, availability, or data practices. Please review the privacy policy of every site you use.

The built-in blocker reduces, but cannot eliminate, advertising, pop-ups and tracking on the pages you visit.

12. Changes to this Policy

We may update this Policy from time to time — for example, if we change advertising partners or add new features. Material changes will be posted on this page with a new "Last updated" date, and where required by law we will seek your consent again. Continued use of the App after an update means you accept the revised Policy.

13. Contact us

Tranquil Mind Technology JSC No. 3, Alley 98, Vu Trong Phung Street, Thanh Xuan Ward, Hanoi City, Vietnam Email: contact@tranquilmind.co

© 2026 Tranquil Mind Technology JSC (@Tranquil Mind Technology JSC). All rights reserved.