Privacy policy
Last updated: 25 October 2026
The short version: Mill Hill Tube has no accounts, no ads and no tracking. We don't know your name, and we don't sell or share data for marketing. The app uses random, anonymous identifiers to run your subscription and keep the service working. If you contact us or send an issue report, we use what you send only to help you and to improve the app.
Who we are
Mill Hill Tube is made by modiff.io Limited, a company registered in England and Wales (company number 09985484), with its registered office at 128 City Road, London EC1V 2NX. We are the data controller for the data described here. Contact: support@millhilltube.app.
What we collect, why, and how long we keep it
| Data | Why | Kept for |
|---|---|---|
| Anonymous app identifiers: a random subscription ID created by RevenueCat, and a random install ID created on first launch. Neither is linked to your name, Apple account details or advertising identifiers. | To check that your subscription is active, and to spot one subscription being shared across many devices (we look at the number of devices per subscription, not who uses them). | While your subscription is active, plus 12 months. Device records: 90 days. |
| Subscription status: plan, trial, start and expiry dates, and whether it's a test purchase. | To give paying subscribers access (contract). | As above. |
| Technical request data: IP address, app version and device type, as part of each request to our servers. | To deliver the live board, and to keep it secure and reliable (legitimate interests). | Short-term service logs, normally up to 30 days. |
| Crash and diagnostic data (Sentry): error details, app version, and device and OS type. When an error happens, a short replay of the app screens leading up to it, with all text and images masked. No IP addresses or other identifying details are sent. | To find and fix bugs (legitimate interests). | Up to 90 days. |
| Issue reports you choose to send: your comment, an optional email address for a reply, an optional screenshot, and the board as shown at that moment. | To investigate the problem and reply if you asked us to (legitimate interests). | Up to 24 months, then deleted. |
| Emails you send us. | To answer you. | As long as needed to resolve your query, then up to 24 months. |
Payments
Subscriptions are bought and billed through Apple's App Store. We never see your card details or Apple ID. Apple tells our subscription provider, RevenueCat, that a purchase happened, and RevenueCat tells us whether your anonymous ID has an active subscription. Apple's own processing is covered by Apple's privacy policy.
Who processes data for us
| Provider | Purpose | Location |
|---|---|---|
| Apple | App distribution, payments, subscriptions | Global |
| RevenueCat | Subscription status for anonymous IDs | USA |
| Supabase | Database: subscription status, device counts, issue reports | EU (Ireland) |
| Cloudflare | API servers and this website | Global network |
| Sentry | Crash reports and diagnostics | EU (Germany) |
Where data is processed outside the UK, it's protected by the UK's adequacy regulations or by approved contractual safeguards, such as the UK International Data Transfer Addendum.
What we don't do
- No accounts, and no names or phone numbers are collected.
- No advertising, and no tracking across other apps or websites. We don't use the advertising identifier.
- No location tracking: the app shows fixed stations.
- We don't sell or share personal data.
Your rights
Under UK data protection law you can ask for a copy of your data, and ask us to correct it, delete it, or stop or limit processing. You can also object to processing based on legitimate interests. Because the app is anonymous, include your issue-report email address or any details that help us find your data when you write to support@millhilltube.app. To cancel a subscription, see Support.
If you're unhappy with how we handle your data, you can complain to the Information Commissioner's Office at ico.org.uk. We'd appreciate the chance to sort it out first.
Children
The app isn't aimed at children under 13, and we don't knowingly collect their data.
Changes
If this policy changes, we'll update this page and the date at the top. Significant changes will also be mentioned in the app's release notes.