Privacy Policy

KnownGood: Test Instrument Record — Last updated: 18 October 2026

D4N LTD ("we", "us", "our") publishes the KnownGood: Test Instrument Record app for iPhone and iPad ("KnownGood" or "the App"). This policy explains what happens to information when you use KnownGood.

The Short Version

  • No sign-up. You don’t sign up or log in, and we never ask for your name, email or phone number.
  • Your records stay with you. Everything you enter is kept in the App and, if you turn on iCloud sync with KnownGood Pro, in your own private iCloud account. We cannot see it.
  • No ads, no analytics, no tracking. KnownGood contains no advertising, analytics or tracking code and does not track you across other apps or websites.
  • No D4N servers. The App never sends your records to us. The only place they go, if you choose, is your own iCloud account.

Who We Are

D4N LTD is a company registered in England and Wales (Company No. 17061504), registered office 3rd Floor, 86–90 Paul Street, London EC2A 4NE. We are registered with the Information Commissioner’s Office (ICO) under registration number ZC132520.

Information Kept in the App

KnownGood is a record of your test instruments, so it stores the records you choose to enter. This can include:

  • Instruments: name, type, make, model, serial number, asset ID, status and the functions and test points you set up
  • Calibration certificates: dates, lab, certificate number, as-found result, notes and any photo or PDF of the certificate you attach
  • Checks: date, method, the reference you checked against and its due date, your readings and the tester name typed for each check
  • Log entries: repairs, damage, loans and other events
  • Settings: your default tester name
  • Pro branding: company name, contact details and logo, used on your PDF exports

This information is kept in the App’s private storage using Apple’s SwiftData framework. It is not sent to us.

Your Signature

If you draw your signature in Settings, it is kept only on the iPhone or iPad where you drew it and added to the PDF records you export. It is not synced to iCloud and is not sent to us. You can clear it in Settings at any time.

iCloud Sync (Optional, KnownGood Pro)

If you have KnownGood Pro and turn on iCloud sync, your records (including attached certificate files) are synced between your devices using Apple’s CloudKit, in a private database in your own iCloud account. This data is held by Apple under Apple’s Privacy Policy and is not accessible to us.

To keep your devices up to date, Apple may send the App silent background notifications when synced data changes. These carry no marketing and are not sent by us. If Pro ends, sync pauses and your records stay in the App.

Reminders

If you allow notifications, KnownGood schedules certificate due-date reminders within the App. Reminders are not sent from our servers, and you can turn them off at any time in iOS Settings.

PDF Exports

PDF instrument records are created by the App. They only leave the App if you choose to share, print or save them, for example by email, AirDrop or the Files app. Once you share a PDF, the recipient’s handling of it is outside our control.

Purchases

KnownGood Pro is sold through Apple’s App Store and processed by Apple using StoreKit. We do not receive your payment details, name or email address. Apple provides us with sales reports and, if you have chosen to share analytics with app developers in your device settings, anonymised and aggregated App Store statistics (such as downloads). These do not identify you.

Information About Other People

Your records may contain the names of other people, such as testers or the lab that issued a certificate. That information is yours to manage: it stays in the App and, if you use iCloud sync, in your own private iCloud account, and D4N LTD does not have access to it or process it on your behalf. Please only record what you need to keep your instrument records.

Information We Do Not Collect

  • We do not collect your name, email address or phone number through the App
  • We do not collect location data
  • We do not use analytics, advertising or tracking SDKs
  • We do not show advertisements
  • We do not sell, trade or transfer your data to third parties
  • We do not store any of your records on our servers

If You Contact Us

If you email us for support, we use your email address and message only to reply and to help with your query. Our lawful basis is our legitimate interest in supporting our users. We keep support emails only for as long as we need them to deal with your query and keep a record of it, and we do not use them for marketing.

Deleting Your Data

  • You can delete instruments, certificates, checks and log entries in the App at any time.
  • Deleting KnownGood removes its data from that iPhone or iPad, including your saved signature.
  • If you used iCloud sync, you can remove the synced data from your iCloud account in iOS Settings → [your name] → iCloud → Manage Account Storage.

Children’s Privacy

KnownGood is a tool for adults who use electrical and gas test instruments at work. It does not knowingly collect personal information from children.

Your Rights (UK GDPR)

As a UK company we handle personal data under the UK General Data Protection Regulation and the Data Protection Act 2018. Because the App does not send your records to us, we hold no App data about you to access, correct or delete. If you have emailed us, you can ask us for a copy of your emails or ask us to delete them.

If you are unhappy with how we handle personal data, please contact us first. You also have the right to complain to the Information Commissioner’s Office at ico.org.uk.

Changes to This Policy

We may update this policy from time to time, for example if the App gains new features. Changes will be posted on this page with an updated “Last updated” date.

Contact

If you have questions about this privacy policy, contact us at:

D4N LTD
Registered office: 3rd Floor, 86–90 Paul Street, London EC2A 4NE
Email: [email protected]
Web: d4n.io

Independent app, not affiliated with or endorsed by any assessment scheme.

Record only. KnownGood does not verify, calibrate or certify any instrument.

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