Privacy policy

The short version

Numelo helps you understand maths. To do that, it sends the questions and photos you submit to an AI service, saves your work, and checks your subscription when needed. We also collect information about how the app is used, and the app tells TikTok when it is installed and opened and when a free trial or subscription starts, so we can measure our adverts. It can notify you when an answer is ready, and the Ideas tab shows a public ideas board hosted by Featurebase.

Please photograph just the question. Avoid including your name, school, face, address or other private information. A photo can contain more than the maths on the page.

Numelo is operated by Matthew Hughes, who is responsible for its handling of your personal information. You can contact him at 12hughesm@gmail.com.

Information the app handles

• Account information: a guest or account identifier, your optional preferred name, sign-in provider identifiers, and information supplied through Apple or Google sign-in. This may include an email address and name, depending on the provider and permissions.
• Your learning content: typed questions, submitted photos, extracted question text, a written description of any diagram, graph or table in a photo, solutions, follow-up questions, tutor replies, saved history and learning preferences.
• Subscription information: products, purchase and renewal events, subscription status, and identifiers used to connect a subscription to your account. Apple processes App Store payments; Numelo does not collect your payment-card details.
• Usage and technical information: actions in the app, request status, usage totals, errors, app and device information, and account-linked analytics identifiers. This includes a device identifier Apple gives to our apps on your device, which our subscription and sign-in providers use to recognise the device and which TikTok also receives. It is not the advertising identifier. Numelo reads the advertising identifier only if you choose Allow when it asks to track, and then sends it to TikTok as described below. Network providers also process connection information needed to handle requests.
• Notification information: if you allow notifications, a notification token Apple gives the app for your device, whether it is a test or App Store build, and your device language. These are stored with your guest or account identifier so we can tell you when an answer or a tutor reply is ready.
• Ideas you share: anything you post, comment or vote on in the Ideas tab. Your guest or account identifier is attached so we can see who asked; other users cannot see it.
• Support information: anything you choose to include when you contact us.

Guest use also creates an identifier. Guest information and account-linked analytics are not necessarily anonymous.

Why the information is used

We use this information to recognise a photographed question, generate explanations, answer follow-up questions, save your work, manage sign-in and subscriptions, provide support, measure how features are used, diagnose failures, prevent misuse, tell you when an answer or reply is ready, and collect ideas for improving Numelo. We also use it to measure which of our adverts lead people to install Numelo and subscribe.

The legal basis depends on the purpose: providing the service you request where necessary to perform a contract; legitimate interests in security, reliability and service improvement where those interests do not override your rights; legal obligations for records we are required to retain; and consent where required. Where processing depends on consent, you may withdraw it without affecting earlier lawful processing. Advert measurement relies on our legitimate interest in knowing which adverts work; the advertising identifier is used only with your permission, given through Apple's tracking prompt.

Services that receive information

Supabase — accounts and saved work

Hosts authentication, the backend and stored learning information, including questions, solutions and conversations. Supabase privacy policy.

OpenAI — reading photos and explaining maths

Receives submitted photos to read the question and, when solving, to see any diagram, graph or table; and question text, a written description of the picture, and relevant solution or conversation context for explanations. It receives the image itself, including any personal information visible in it. Numelo's backend does not keep submitted photos: a photo sent for solving is held in memory only for that request. The current integration disables response storage for photo reading and for any solve that includes a photo, and enables it for other generation. OpenAI documents default abuse-monitoring retention of up to 30 days, with exceptions for legal or safety needs, and a default 30-day period for stored responses. Disabling response storage does not disable all provider retention. Account-specific controls and deletion arrangements remain to be confirmed. See OpenAI's API data controls and privacy policy.

RevenueCat — subscription management

Receives an app user identifier and subscription and purchase information to manage access. An analytics identifier connects relevant subscription events with PostHog. The integration does not intentionally attach your homework, photos, name or email to RevenueCat. RevenueCat privacy policy.

PostHog — app analytics

Receives app events, account-linked identifiers and technical information to help us understand usage and failures. The app's event integration does not intentionally send homework content, photos, names or email addresses. Session replay and automatic screen capture events are disabled in the current configuration. PostHog privacy policy.

Apple — notifications

When an answer or tutor reply is ready, our backend sends a notification through Apple's push notification service using your device's notification token. The notification says only that your answer or reply is ready, together with an identifier the app uses to open the right question. It does not contain your question, photo or solution. Apple privacy policy.

Featurebase — ideas board

The Ideas tab shows our ideas board, which Featurebase hosts. When the board loads, Featurebase receives technical information such as your IP address, device and browser details and language, and your guest or account identifier, which Featurebase stores and shows only to us. Featurebase may use its own cookies and analytics; these stay on your device until you delete the app. If you post, comment or vote, Featurebase receives what you write. Posts appear without your name. Posts and comments are public as soon as you post them, so anyone who opens the board can read them. We remove posts or comments that are reported to us or that break our rules. Please do not include your name, school or other personal details. Featurebase privacy policy.

Apple and Google — sign-in; Apple — purchases

Process information when you use their sign-in services. Apple also processes App Store transactions. Their own privacy notices explain their handling of information: Apple and Google.

Apple Search Ads — install attribution

If you install Numelo after tapping an advert on the App Store, Apple provides a token that the app exchanges for the campaign, ad group and keyword that led to the install. These identify the advert, not you, and are recorded alongside app events so we can tell which adverts are worth running. For these Apple adverts no advertising identifier is used and nothing is shared with other advertising networks. Apple advertising and privacy.

TikTok — advert measurement

We advertise Numelo on TikTok. The app includes TikTok's software, which tells TikTok when the app is installed and opened, and when a free trial or a subscription starts, so we can tell which adverts work. With each of these it sends technical information: your device model, iOS version, language and region, IP address, the device identifier described above, and a random identifier that TikTok's software creates. It does not send your name, email address, questions, photos or solutions. These events are sent whether or not you allow tracking. Once, after you start a free trial, the app asks whether it may track you. If you choose Allow, your device's advertising identifier is sent as well, which lets TikTok match you to an advert you saw. If you choose Ask App Not to Track, it is not sent, and Numelo works the same either way. You can change your answer at any time in Settings, under Privacy & Security, then Tracking. Apple also sends TikTok install reports that identify neither you nor your device. TikTok handles this information under its own policy. TikTok privacy policy.

Information may also be disclosed where necessary to comply with applicable law or protect users and the service. Provider privacy notices supplement this page; they do not replace Numelo's responsibility for its own use of your information.

Storage and account deletion

Saved questions and conversations are retained to make your learning history available. You can request account deletion in the app or contact us for help. The account-deletion workflow removes the profile and saved learning content from the active database and requests removal of the sign-in identity and identified analytics data. Provider cleanup may complete separately if a request needs retrying.

We delete your notification token when you delete your account, and the app asks us to delete it when you sign out. Ideas and comments you post stay on the board after you delete your account; contact us and we will remove them.

Numelo's server does not keep submitted photos. The app keeps a copy of each question photo on your device, with the saved question, so you can see it next to the solution. It stays on the device, is not included in iCloud backups, and is removed when you delete your account or the app. Copies may also exist with the processing provider as described above. Deleting a Numelo account is not a promise of immediate removal from all provider systems or backups.

Our retention policy sets a period of 90 days after account deletion for minimal usage records kept for abuse prevention. These records contain account identifiers and usage totals, rather than question or conversation content. Automated deletion at that point has not yet been verified; contact us if you need confirmation that your retained records have been removed.

Records required for UK sole-trader tax reporting will be retained for five years after the 31 January filing deadline for the relevant tax year, or longer where a specific legal requirement applies. This period does not automatically apply to every account-linked subscription event. Fixed retention periods for other operational billing records, backups, technical logs, guest data and provider-held records have not yet been established. Contact us for information about a particular record or a deletion request.

Deleting your account does not cancel an App Store subscription. Manage or cancel it through your Apple account's subscription settings.

Where information is processed

The services used by Numelo, including TikTok, may process information outside the UK. Contact us for details of where your information is processed and the safeguards applicable to those transfers.

Younger users and families

Numelo is intended for secondary-school students aged 13 and over. It is not directed at children under 13, and we do not knowingly collect information from them. Advert measurement, described under TikTok above, applies to every user. If you are a parent or guardian and believe a child under 13 has used the app, contact us and we will delete their information.

Please avoid including names, school details or other identifying information in submitted photos and questions. If you are concerned about information a child has submitted, contact us to request help or deletion.

Your choices and rights

You can choose typed entry instead of submitting a photo, manage camera and photo permissions in your device settings, choose whether to allow tracking for advert measurement (in Settings, under Privacy & Security, then Tracking), turn notifications on or off in your device settings, choose whether to use the Ideas tab, and request account deletion. Depending on the circumstances and applicable law, you can ask to access, correct, delete, restrict or receive a portable copy of your personal information, or object to processing. These rights are subject to legal conditions and exceptions.

Email 12hughesm@gmail.com to make a request. We may need to verify that the information belongs to you. You can also complain to the UK Information Commissioner's Office or the relevant regulator where you live.

This website

This page does not add analytics, advertising cookies, forms or third-party fonts. It is hosted on GitHub Pages; GitHub may process technical connection data, such as an IP address, to operate and secure the service. See the GitHub privacy statement.

Contact and updates

Matthew Hughes
12hughesm@gmail.com

Changes will be published on this page with an updated date. Material changes will also be brought to users' attention where appropriate.