Privacy Policy

Last updated 10 October 2026

This policy explains what the Lumn app (iPhone and Android), lumnapp.com and join.lumnapp.com collect, why, who helps us run it, and what you can do about it. Lumn is run by Leonardo Butera Andreu (“we”, “us”), who is responsible for your information.


1. What we collect in the app

  • Your account: your name and email address, and how you sign in (email and password, Google or Apple).

  • Your answers when you set up Lumn, and the Path you choose.

  • What you do on your Path: which daily tasks, challenges and weekly goals you complete, and your progress.

  • Your journal entries, the moods you log, and the reflections and weekly summaries made from them.

  • Your subscription status: which plan you are on, when it started and when it renews or ends. We never see your full card details; the App Store, Google Play or Stripe handles payment.

  • Notification settings and a notification ID so we can send the reminders you ask for.

  • Usage statistics through PostHog, from app version 4.0.3: when you open the app, which screens and steps you reach (for example an onboarding screen, the subscription screen, a completed day or week, a submitted journal entry, or a rating request), the Path and plan you choose, whether you allowed notifications, and whether you came from the website or a creator code. PostHog also records device and app details such as your device model, screen size, operating system, app version, language, time zone, connection type and mobile carrier. These statistics are tied to a random ID made on your phone and, once you sign in, to your account ID; never to your name or email, and they never include your journal entries or anything else you write. PostHog does not keep your IP address or work out your location, and the app does not record your screen.

  • Advertising measurement through Meta, from app version 4.0.4. Meta Platforms, which runs Facebook and Instagram, has software built into the app so we can tell whether our ads there bring people to Lumn. Each time you open the app or come back to it, this software tells Meta that the app was opened, and the first time, that it was installed. With that, Meta receives a random ID that Meta’s software makes on your phone, your IP address, and device and app details such as your device model, system version, app version, language, time zone, mobile carrier and screen size. On Android it can also include how the app was installed from Google Play. On Android it also sends your phone’s advertising ID, unless you have deleted it. On iPhone it does not collect your advertising ID, and Lumn never asks to track you. On Android, the app also gives our subscription provider RevenueCat that random ID, which it keeps with your subscription record. The app sends Meta no other events: not your purchases or free trials, and never your name, email, account ID, journal, Path or anything you write. If your phone’s region settings include a country in the EU, the EEA, the UK or Switzerland, the app sends Meta none of this. That follows your phone’s settings, not where you are. Separately, on iPhone, if you came from one of our ads, Apple may tell Meta about the install without saying who you are; that comes from Apple, not from the app. On any phone, Meta’s software may still contact Meta when the app starts, to fetch its own settings, and that shows Meta your IP address. Meta also uses this information under its own Data Policy (facebook.com/privacy/policy).


2. What we collect on the website

  • If you use the contact form: your name, email address, the type of message and what you write.

  • Page-view statistics through Vercel Web Analytics. It does not use cookies and does not follow you across other sites; it counts visits to our pages in aggregate.

  • If you subscribe on join.lumnapp.com: your setup answers, your email and your subscription, as in section 1. Payment is handled by Stripe.

  • On join.lumnapp.com only, the Meta Pixel and Meta’s Conversions API, to measure whether our ads on Facebook and Instagram work. We send Meta an event when you visit a page, get a First Entry reading, start checkout, create your account, start a free trial, and each time your subscription is charged. With each event we share the page address, your IP address, browser details, Meta cookie IDs, a scrambled (hashed) copy of your email address and account ID, and, for checkout, free trials and charges, the plan you chose and the amount. We do not share your setup answers, your Path, your journal or your card details. To make this work, we also keep your IP address, browser details and Meta cookie IDs with your subscription at Stripe. We send nothing to Meta, from your browser or from our server, for visitors in the EU, the EEA, the UK or Switzerland, or for anyone whose browser sends a Global Privacy Control signal. Blocking cookies only stops the Meta cookie IDs; a tracker blocker stops the part that runs in your browser but not the events our server sends. To opt out completely, email lumnsupport@gmail.com and we will stop. Meta also uses this information under its own Data Policy (facebook.com/privacy/policy). The Lumn app does not use the Meta Pixel. From app version 4.0.4 it uses Meta’s app software instead, as described in section 1. Its rules differ from the website’s: the app does not read Global Privacy Control; instead you can stop the app sending Meta your app opens with a switch in the app (see section 9).


3. Why we use it

  • To run Lumn for you: your Path, your daily tasks, your journal, your reminders and your subscription.

  • To give you a reflection after a journal entry and a weekly summary (see section 4).

  • To answer you when you write to us, and to keep Lumn working and secure.

  • To understand, from usage statistics, where people get stuck in the app so we can improve it.

  • We do not sell your information and there are no ads inside Lumn. We measure our ads in two ways only. We use Meta’s measurement, in the app from version 4.0.4 (section 1) and on join.lumnapp.com (section 2). And on iPhone, from app version 4.0.3, we ask Apple whether you came from one of our App Store ads (section 5).

  • Where the law asks for a legal basis (for example in the EU or the UK), we use your information to perform our agreement with you (your account, Path, journal and subscription), with your consent (notifications and journal reflections, which you can stop at any time), and for our legitimate interests in keeping Lumn working and secure and in improving it from usage statistics.


4. Your journal and the reflections

  • When you ask for a reflection on a journal entry, we send automated services run for Lumn the entry’s text, the question you answered, the type of journal entry and its tags, with your account ID. They send back the reflection you see. Your weekly summary is built the same way from your week’s entries and progress, and your daily questions are written for your Path. No person at Lumn reads your journal to do this.

  • Those services run on Google Firebase, and the text is processed by OpenAI on our behalf. We do not allow it to be sold or used for advertising. Under OpenAI’s terms for this kind of service, it does not use the text to train its models, and it may keep it for up to 30 days to check for abuse before deleting it.


5. Who helps us run Lumn

  • OpenAI: writes the reflections, weekly summaries and daily questions in section 4.

  • Google Firebase (Google LLC): sign-in, the database that stores your account, Path, journal and progress, and the automated services in section 4.

  • RevenueCat: keeps track of your App Store and Google Play subscription status. On iPhone, from app version 4.0.3, it also asks Apple whether you came to Lumn from one of our ads on the App Store, using a token from Apple that does not identify you. On Android, from app version 4.0.4, it also keeps Meta’s random ID with your subscription record, as in section 1.

  • Apple (App Store) and Google (Google Play): take payment for in-app subscriptions under their own privacy policies.

  • Stripe: takes payment for web subscriptions on join.lumnapp.com.

  • Meta Platforms: measures our Facebook and Instagram ads, in the app from version 4.0.4 (section 1) and on join.lumnapp.com (section 2). Meta also uses this information under its own Data Policy.

  • OneSignal: sends the notifications and reminders you turn on.

  • PostHog: counts which screens and steps people reach in the app, as in section 1, so we can see where Lumn needs to improve.

  • Vercel: hosts lumnapp.com and join.lumnapp.com and provides the cookieless page analytics.

  • Web3Forms: delivers contact-form messages to our inbox.

  • Apart from Meta, as described above, we share information with these providers only so they can do these jobs, and when the law requires it.

  • Lumn is run from the United States, and these providers store and process information mainly in the United States. If you use Lumn from elsewhere, your information is transferred there; where the law requires it, we rely on our providers’ standard data-protection terms (such as the European Commission’s standard contractual clauses) to protect it.


6. How long we keep it, and deleting your account

  • We keep your information while you have an account.

  • You can delete your account in the app from Profile > Account Settings. It asks you to sign in again, then deletes your journal entries, mood logs, saved readings, notifications, Path progress, tasks and task completions, weekly goals and weekly summaries, and your profile (name, email, answers and Path), deletes your notification record and your sign-in, and cancels the reminders on your phone. If you signed in with Apple, it also asks Apple to remove Lumn’s access to your Apple ID.

  • Deleting your account does not cancel a subscription: cancel it in the App Store, Google Play or on join.lumnapp.com. Apple, Google, Stripe and RevenueCat keep their own purchase records under their policies.

  • Contact-form messages and emails stay in our inbox until we delete them. After you delete your account, copies can remain in our providers’ routine backups for a limited time until they are overwritten.

  • Deleting your account does not remove the install and open events Meta has already received (section 1), or, on Android, Meta’s random ID kept with your subscription record at RevenueCat. Meta keeps its data under its own Data Policy.

  • If you can’t use the app, email lumnsupport@gmail.com from your account’s email address and we will delete the account for you.

  • Usage statistics in PostHog (section 1) are not removed by deleting your account in the app; we delete them if you ask us before you delete your account (see section 9). Otherwise they stay with PostHog, under an account ID that is no longer linked to your name or email, for as long as PostHog keeps them under its own retention rules.


7. Keeping it safe

  • Your information travels encrypted (HTTPS) between your device and our services, and our providers, including Google Firebase, encrypt it where they store it.

  • Access to your account data is restricted to your own signed-in account by our database rules.

  • No system is perfectly secure. If something goes wrong that affects you, we will tell you as the law requires.


8. Children

  • Lumn is for people aged 13 and over. We do not knowingly collect information from children under 13; if you believe a child under 13 has an account, email us and we will delete it. If you are under 18, please use Lumn with a parent’s or guardian’s permission.


9. Your choices and rights

  • You can see and change most of your information in the app, turn notifications off in your phone settings, and delete your account at any time.

  • You can ask us for a copy of your information, to correct it or to delete it by emailing lumnsupport@gmail.com. We will reply as soon as we can.

  • Deleting your account in the app does not yet remove your usage statistics from PostHog. To have them deleted, email us from your account’s email address before you delete your account, and we will delete them. Statistics that were never tied to an account carry only a random ID from your phone and cannot be traced back to you.

  • Depending on where you live (for example in the EU, the UK or California), you may also have the right to know what we hold, to restrict or object to how we use it, to receive it in a portable form, and to complain to your data protection authority. We do not sell your personal information. Under California law, sending events to Meta for advertising counts as “sharing”. That covers the website events in section 2 and, from app version 4.0.4, the app’s install and open events in section 1. On the website, you can opt out by emailing lumnsupport@gmail.com, and we honour Global Privacy Control. In the app, use Profile > Privacy & Security > Limit ad measurement (below). We will not treat you differently for using these rights.

  • In the app, from version 4.0.4, you can stop the app sending Meta your app opens: Profile > Privacy & Security > Limit ad measurement. When it is on, the app sends Meta no app opens or installs and removes the Meta ID it gave RevenueCat; on any phone, Meta’s software may still contact Meta when the app starts, to fetch its own settings. The app does not read Global Privacy Control. On Android, you can also reset or delete your advertising ID in your phone’s settings (usually Settings > Google > Ads, or Settings > Privacy > Ads).


10. Changes to this policy

  • If we change this policy we will update the date at the top. If a change is significant we will tell you in the app or by email before it applies.


11. Contact