Privacy policy

Last updated 14 October 2026

This policy covers the Maths & Martians app for iPhone, iPad and Android, and this website. I’m the developer, a sole trader, and I’m responsible for it. You can reach me at dvrmmrdev@gmail.com.

What stays on your device

Each cadet’s name, appearance, role, school year, crystals, shop items, colony and badges are saved in the app’s own storage on the device. So is their maths progress: how often each fact has been answered right or wrong, a day-by-day count of questions answered over the last 60 days, and their Times Tables Check practice scores. The progress report in Parent Settings is worked out from this, on the device. So are the settings a grown-up chooses, such as the Earth region, the times tables to focus on and which topics are switched on. I don’t receive any of this. Deleting the app removes it.

A cadet’s name doesn’t need to be a child’s real name, and I’d suggest a nickname or a space name.

Your phone’s own backup (iCloud, or Android’s backup to Google) may include app data, depending on your device settings. That’s between you and Apple or Google. I don’t receive it.

Sharing the progress report

With Premium, a grown-up can share the progress report as text through the device’s share sheet, for example by email or message. It goes only where the grown-up sends it. The app doesn’t send it anywhere by itself.

Google Drive backup (optional, for grown-ups)

Backup is off unless a grown-up opens Parent Settings, then Backup & Restore, and signs in with Google.

• What is saved: the cadet data described above, as one file.
• Where: a hidden folder in the grown-up’s own Google Drive that only this game can open. It never appears among their normal files.
• What access the game asks for: the Google Drive “app data” permission (drive.appdata). It lets the game read and write its own hidden folder and nothing else. It can’t see your other files.
• What I receive: nothing. The sign-in happens with Google. I never see your Google password, your email address or the backup itself.

Maths & Martians’s use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

In plain terms: I don’t read your backup, I don’t use it for advertising, I use it only to run the backup and sync feature you can see in the app, and I don’t pass it to anyone.

Removing a backup

Deleting a cadet in the app is carried across on the next backup. To remove the backup file itself, open Google Drive in a desktop web browser, choose the gear icon, then Settings, then Manage apps. Find Maths & Martians, choose Options, then Delete hidden app data. This can’t be done from the Drive mobile app. You can also remove the game’s access from your Google Account’s security settings.

Purchases

There is one optional, one-time purchase, Premium. The app store (Apple or Google) takes the payment, so I never see card details or your name. To check that a purchase has been made, the app uses a service called RevenueCat, run by RevenueCat, Inc. in the United States. It receives an anonymous ID that the app makes up on your device, plus purchase information from the store. It doesn’t receive your name, your email address or anything about your cadets. RevenueCat’s own policy is at revenuecat.com/privacy.

Reading questions aloud

Questions are read out by your device’s built-in speech engine. The app doesn’t record audio, and it doesn’t ask for the microphone.

What the app doesn’t do

• No advertising, and no advertising or analytics tools of any kind.
• No accounts, sign-ups or email addresses inside the app.
• No location, camera, microphone, contacts or photos.
• No chat, messaging or social features, so nothing a child types can reach anyone else.
• No selling or sharing of data. I don’t have any to sell.

One thing the app loads from elsewhere

When the app opens, it downloads its styling code from the Tailwind CSS content delivery network (cdn.tailwindcss.com). Your device makes that request directly, so that service can see your device’s IP address and basic technical details, as any web server does when it’s asked for a file. Nothing about your cadets or settings is sent with it.

Children

The game is made for children in Reception to Year 6, to be used with a parent or guardian nearby. There’s no account and I collect no personal information from children. Parent Settings, the progress report, backup and purchases sit behind a grown-up maths question. I don’t knowingly collect personal information from children, and if you think I have, please email me and I’ll delete it.

This website

The website is a few static pages. It sets no cookies, has no analytics or advertising, and hosts its own fonts rather than loading them from another company. My web host keeps standard server logs (such as IP addresses and the pages requested) to run and secure the service, under its own policy.

If you email me, I use your address and message only to reply and to keep a record of the conversation, and I delete it when it’s no longer needed.

Your rights

Because I don’t hold personal information about people who play the game, there is normally nothing for me to look up or delete. Your cadets are on your device, and any backup is in your own Drive, where you control it. For emails you’ve sent me, you can ask to see, correct or delete them. If you’re in the UK and unhappy with how I’ve handled something, you can complain to the Information Commissioner’s Office at ico.org.uk/make-a-complaint.

Changes

If I change this policy, I’ll update the date at the top.

Contact

dvrmmrdev@gmail.com