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Privacy Policy: Lumilo

Last updated: November 4, 2026

Lumilo: AR Draw, Trace, Sketch ("the app") is developed by Krillo ("we", "us"). This policy explains what data the app handles. The short version: your library, drawings and timelapse videos stay on your phone. A photo or a line of text leaves your phone only when a Pro user asks the app to draw a sketch with AI (Clean sketch or AI Creator). Everything else that leaves the app is what is needed to run subscriptions, anonymous usage statistics, and measuring the ads we buy for Lumilo on Facebook and Instagram.

Photos and text you turn into sketches with AI

These two features are part of Lumilo Pro. When you use Clean sketch, the one photo you chose (reduced to at most 1024 pixels on its long side) is sent over an encrypted connection to our own server, the Krillo scanning worker krillo-ai-scan, which runs on Cloudflare. When you use AI Creator, the text you typed (up to 200 characters) is sent the same way. Before the first use the app shows a screen that explains this and asks you to agree.

With the photo or the text the app sends the detail level you picked and the same anonymous ID that is used for subscriptions. Our server uses that ID to check with RevenueCat that your Pro plan is active (it remembers the answer for up to 15 minutes) and to count your AI sketches against the limits in the Terms of Use. The counters are kept under that ID and expire on their own.

From our server the photo or the text goes to Google's Gemini API, which draws the sketch. The sketch comes back to your phone and is saved in your library there. We use the photo or text only to produce that sketch: not for statistics, advertising or training. We do not store it. Our server holds it in memory for the few seconds this takes and does not write it to a database or a file. Our logs record technical facts about the request (that a sketch was made, photo or text, detail level, time, cost, your plan type) and not the photo, the text or the sketch. If a text is declined by our blocklist of franchise, character, celebrity and brand names, the blocklist word it matched is logged. Under the Gemini API terms Google does not use these requests to improve its products and keeps them for a limited time only to detect abuse (Gemini API terms, Google's privacy policy). Our server has no second AI provider for this feature.

Please upload only photos you have the right to use, and do not send photos of other people without their consent. We do not extract biometric data from photos: no face recognition, no face geometry, no identification.

Outline, the outline of your own photo made on your phone, and tracing a photo in camera mode work on the phone, and those photos are not sent anywhere. If an AI sketch is offensive or wrong, tap Report: we receive the reason you chose from a short list, not the photo, the text or the sketch.

What stays on your device

Your library (photos you added, outlines and sketches), photos of finished drawings, timelapse frames and videos, favorites, your level and course progress, your reminder settings and your choices in the app are stored on your phone. Usage statistics record some of these as events: which course day was opened or finished, your answers to the questions at the start, which drawing tools you used and whether you allowed notifications. Your photos, sketches, drawings and videos themselves stay on your phone. They are deleted when you delete them or uninstall the app. The camera picture you see while tracing is shown on screen and is not recorded or sent anywhere; timelapse videos are made from frames saved on your phone and have no sound. A video leaves your phone only if you share it yourself with the system Share button.

The app has no account and no sign-up. It does not use GPS or ask for your location, and it does not access your contacts, files or microphone.

Downloading the sketch library

Sketches and lessons are downloaded from our content server, hosted by Cloudflare, and kept on your phone so they open again without a connection. The server sees which file is requested and your IP address, as any website does to deliver a file. No other data goes with the request.

Reminders

If you allow notifications, the app schedules reminders on your phone itself. There is no push-message server. Usage statistics record whether you allowed notifications, which kind of reminder was scheduled (a lesson of the day, a course day or a trial reminder) and whether you opened it. The reminder text is built into the app. The app also asks Android to start after a reboot so that scheduled reminders are restored.

Usage statistics

To see which features people actually use, Lumilo sends anonymous usage events to PostHog, an analytics service. An event records that something happened in the app, such as that a sketch from the library was opened (with its catalog number, category and difficulty), which mode was chosen, whether camera permission was granted, how long a drawing took and whether it was finished, whether a sketch was made on the phone or with AI and how long it took, whether a timelapse was saved or shared, which day of the course was opened, whether the subscription screen was shown, which part of the app opened it and how it was closed, which drawing tools were used and how long the camera took to start, and whether you agreed to send a photo or text to AI (not the photo or text). Each event carries properties such as the app version, your device platform and device model, the Android OS version, the language the app is displayed in, the language of your phone, when the app was installed (the date), the first app version you used, your subscription status (free, trial, paid or lifetime), and the same anonymous ID that is used for subscriptions. These examples are illustrative rather than a complete list.

If you arrived from an ad or from a link someone shared from Lumilo, Google Play passes the app the campaign tag of that link, and the app stores it with your usage statistics. It tells us which campaign brought you to Lumilo. For ads on Facebook and Instagram the tag is an encrypted record of the ad click added by Meta; we keep only its first 120 characters and cannot read it. It is not an advertising identifier.

Subscription events (a trial starts, converts, renews or is cancelled) are passed from RevenueCat to our analytics under the same anonymous ID. They carry the product, the price and the store, never your payment details.

What does not go into statistics or to Meta: your photos, the text you type in AI Creator, sketches, drawings, timelapse videos and frames, and your feedback. We record that a sketch was made and how, not the picture. The photos you add to your own library are never named in events.

We do not collect your name, email, Google account or phone number. Our analytics service discards your IP address rather than storing it, so we do not derive your location from it. Usage statistics are processed on servers in the European Union and are not sold. To have your statistics and, if you bought Pro, your purchase record deleted, see Delete your data.

Measuring our ads (Meta)

Lumilo shows no ads. We do buy ads for Lumilo on Facebook and Instagram, and to learn which of them bring people who actually use the app, the app includes the Meta SDK (Facebook SDK). It sends to Meta Platforms:

Like any service the app connects to, Meta also receives your IP address. From the IP address and the time zone Meta can tell roughly where you are. Meta uses this data to report to us how our ads perform and to show our ads to people likely to use the app, and it may link it to your Facebook or Instagram account under Meta's Privacy Policy. The app does not send Meta the anonymous ID we use for statistics and subscriptions, and it does not send the start of a trial or a purchase. Those two come from RevenueCat, as described under Subscriptions.

You can limit this: delete or reset your advertising ID in Android Settings → Privacy → Ads (once it is deleted, the SDK receives no advertising ID), and review or clear what apps share with Meta under "Your activity off Meta technologies" in your Facebook or Instagram settings. We cannot delete Meta's copy for you, because it is not linked to any identifier we hold.

Subscriptions

Subscriptions and the one-time Lifetime purchase are sold and processed by Google Play. We never see or store your payment details.

To show the correct prices and to know whether Pro is active, the app uses RevenueCat, a subscription-management service. It receives a randomly generated anonymous app user ID (the same one used for the statistics above, so there is one anonymous identifier, not two), your Google Play purchase receipt and subscription status, and technical details such as app version, OS version, country and language. We use this to unlock Pro on your device, to restore purchases, to check your plan when you use AI sketches, and to see anonymous sales numbers. See RevenueCat's privacy policy and Google's privacy policy.

RevenueCat to Meta. To measure our ads, the app also lets RevenueCat collect your device's advertising ID, the identifier that Meta's SDK assigns in this app and your IP address. RevenueCat then passes the start of a free trial, purchases and renewals (the product, the amount and the currency) from its servers to Meta together with those identifiers, so Meta can tell which ad led to a purchase. This is separate from the events the app sends to Meta itself, and Meta may use it as described in the previous section. The same limits apply: you can delete or reset your advertising ID in Android Settings.

Permissions

Feedback

The in-app survey and the Support button open an email in your own mail app, addressed to [email protected]. We receive it only if you send it.

Third-party services

The app includes RevenueCat and Google Play Billing for purchases, PostHog for the anonymous statistics described above, and the Meta SDK to measure the ads we buy for Lumilo. AI sketches are processed through our own worker krillo-ai-scan (hosted by Cloudflare) and Google's Gemini API. The library is delivered by Cloudflare. The app shows no ads. The Play Store data-safety label matches what is described here.

AI results are not perfect

AI sketches are generated by an automated model. They can be inaccurate or unexpected. If one is offensive or wrong, use Report. See the Terms of Use.

Purchases and cancellation

Some sketches and lessons are free. Lumilo Pro unlocks the rest, and the AI features. It is sold as an auto-renewing subscription (weekly or yearly, some with a 3-day free trial or a reduced first week) or as a one-time Lifetime purchase. The exact prices and terms are in the Terms of Use and on the purchase screen. You can cancel a subscription anytime in Google Play → Subscriptions, or from Settings inside the app, which opens that page. Uninstalling the app does not cancel a subscription. We never charge you outside Google Play.

Children

Lumilo is for people aged 13 and older and is not directed at children under 13. The app has no account, the usage statistics described above are anonymous, and the advertising ID goes to Meta and RevenueCat only as described above. If you are a parent and believe a child under 13 has used the app, write to us and we will delete what we hold.

Contact

Questions about this policy: [email protected]

Changes

We will post any changes to this policy at this same URL with an updated date.