Legal
Opus Air Privacy Policy
What Opus Air collects, why, where it goes, and the rights you have over it. This policy covers the app only.
Effective date: 1 August 2026
Our legal documents are published in English only, and the English text is the authoritative version. If you would like help understanding any part of it, email [email protected].
1. Who we are
Opus Air is published by Opus Accountancy Limited, a limited company registered in England and Wales, company number 03956240, with its registered office at Bretton House, Bell Meadow Business Park, Park Lane, Pulford, Chester, CH4 9EP.
Opus Accountancy Limited is the data controller for the personal data described in this policy. That means it decides what is collected and why. This policy covers the Opus Air app only. It does not cover any website, and it does not cover any other app.
- App
- Opus Air (iOS, watchOS)
- Published by
- Opus Accountancy Limited
- Company number
- 03956240
- Registered office
- Bretton House, Bell Meadow Business Park, Park Lane, Pulford, Chester, CH4 9EP
- Data protection contact
- [email protected]
2. What this app collects
Opus Air has no accounts, no sign-in, no analytics, no advertising, and no tracking. We do not sell or share your data, and nothing you do in the app is linked to your name.
To tell you the weather and pollen where you are, the app needs an approximate location. To keep a paid subscription working, it needs to know that this install has paid. That is the whole of it.
The app authenticates to our server using Apple App Attest, which proves the request comes from a genuine, unmodified copy of Opus Air on real Apple hardware. This produces a per-install identifier that carries no name, no email and no link to your Apple Account or to any other app. It is bound to this device: it is never copied to another device and is excluded from your iCloud backup. If you reinstall the app on the same device it may continue to be used.
We store that identifier and a hash of the access token — never the token itself. It exists to stop our paid weather and pollen feeds being abused, and to know which install holds a subscription.
Lawful basis: legitimate interests — preventing abuse of a paid third-party feed.
3. What this app does not collect
No name, email, address or phone number. No account. No contacts, photos or calendar. No advertising identifier. No analytics or crash-reporting SDK. No third-party trackers. Opus Air does not track you across apps or websites and shows no App Tracking Transparency prompt, because there is nothing to ask for.
4. Why, and the lawful basis
The UK GDPR requires a lawful basis for processing personal data. These are the bases we rely on, for the data that reaches us:
- your location
- Contract. To fetch the pollen, air quality and forecast where you are.
- identifiers that could be used to recognise you or your device
- Legitimate interests. To prove the request comes from a genuine, unmodified copy of the app, and to stop the paid pollen and weather feeds being abused.
- your purchase history
- Contract. To verify a purchase with Apple and unlock what you paid for.
Things that stay on your device
Your allergen profile (which pollens you react to, your alert threshold) is information about your health. It is created and used on your device and syncs through your own iCloud account using Apple’s key-value store. It goes to Apple as your storage provider, not to us — we hold no copy, no credential for your iCloud, and no means by which we could ever read it.
Your score history is stored locally on your device and is not uploaded.
Notifications are decided on your device. Pollen alerts are evaluated locally; we are not told when one fires.
Location
If you grant location access, the app reads your position and rounds it to roughly a 1 km grid before it leaves your device. That rounded coordinate is sent to our server to fetch pollen and air-quality data, and to Apple to fetch the weather forecast.
We do not store your location history. The rounded coordinate is used to answer the request and is retained only in a short-lived cache keyed by grid square, shared across everyone in that square.
If you deny location access, the app shows a clearly-labelled London default and tells you on screen that it is a default rather than your position. It keeps working; it simply does not know where you are.
You may also save named places manually and use the app without granting location at all.
Lawful basis (UK GDPR): performance of a contract — you asked us for the forecast where you are.
Purchases
If you subscribe, Apple gives the app a signed transaction receipt, which we send to our server to verify the purchase and unlock the feature. We store the resulting entitlement state, the subscription’s expiry, and Apple’s opaque transaction identifiers.
We never see your payment details, card, or billing address — Apple handles payment entirely and does not share those with us.
Lawful basis: performance of a contract — delivering what you paid for.
Transfers outside the United Kingdom
Some of the parties above are based outside the United Kingdom, or process data on infrastructure that is. Where personal data is transferred outside the UK, we rely on the UK’s adequacy regulations for the destination country where they apply, and otherwise on the International Data Transfer Agreement, or the International Data Transfer Addendum to the European Commission’s standard contractual clauses, together with any additional safeguards the transfer requires.
Children
Opus Air is not directed at children and collects nothing that identifies a person. It is rated suitable for all ages.
How long data is kept
Rounded-coordinate forecast cache: minutes to hours, then discarded.
Per-install identifier and token hash: while the install is active; tokens expire and are deleted.
Entitlement and subscription state: while the subscription is active, plus the period we must keep records for tax and accounting.
Server request logs: method, path, response status and a truncated install prefix. No coordinates and no readings. Kept short-term for operating the service.
Your IP address, when the app first enrols: recorded once, to cap how many times the app can enrol from one address and stop the paid feeds being abused. Deleted automatically once it falls outside that 24-hour window. Lawful basis: legitimate interests.
Security
Traffic between the app and our server is encrypted (HTTPS) and authenticated with Apple App Attest. Access tokens are stored hashed on the server and in the device Keychain on your phone. Our server holds no name, email or payment detail, so there is nothing of that kind to lose.
Your rights over your personal data
Under UK GDPR you may request access to, correction of, or deletion of your personal data, object to processing, or request portability, and you may complain to the Information Commissioner’s Office.
A practical note on erasure: because the app has no accounts, we usually cannot connect a person to the anonymous per-install identifier — which cuts both ways. It is why we hold so little about you, and it is why we cannot find your record from your name or email alone.
To have your record erased, send us the install identifier — the app shows it in Settings — and we will delete it. That is the reliable route, and it is the one to use.
Deleting the app is not a substitute. It stops the app sending us anything further, and the identifier never moves to another device, but the credential is held in your device’s keychain and we cannot guarantee that removing the app removes it: reinstalling on the same device may continue with the same identifier.
Getting help with the app
Questions about how Opus Air works, rather than about your personal data, are answered on the support page at opus.expert/opus-air/support, which also explains how to ask for your data to be deleted.
Contact and complaints
If you have any question about this policy, or would like to discuss how we process personal data, email [email protected]. You can also write to us at Bretton House, Bell Meadow Business Park, Park Lane, Pulford, Chester, CH4 9EP.
You also have the right to complain to the Information Commissioner’s Office, the UK supervisory authority for data protection. We would ask you to raise the matter with us first so that we have the chance to put it right.
- Information Commissioner’s Office
- Information Commissioner’s Office, Wycliffe House, Water Lane, Wilmslow, Cheshire SK9 5AF. Telephone 0303 123 1113. ico.org.uk/concerns
Changes to this policy
If we change this policy we will update the effective date above, and note material changes in the app’s release notes.