Pre-release. Door Supervisor Mock Tests is in development and is not in the App Store yet.
Who we are
Door Supervisor Mock Tests is made by XFour IT Limited, trading as XFour Labs ("we", "us"). We are a company registered in England and Wales, number 11776254. Our registered office is 100 Berkshire Place, C/O KT Wells Ltd, Winnersh Triangle, Wokingham, RG41 5RD, United Kingdom. We are the controller of the personal data described here, under UK data protection law (UK GDPR and the Data Protection Act 2018).
Questions about this policy: gdpr@xfour.co.uk.
The short version
Door Supervisor Mock Tests has practice questions and mock exams for the SIA Level 2 Door Supervisor qualification. It is not affiliated with the SIA or any awarding body.
There is no account and no sign-in.
- We do not collect: any personal information. The app makes no network connections of its own.
- We do not collect: analytics, crash reports, advertising IDs. No ads.
What we collect, where it goes, and how long we keep it
| Data | Where it is stored | Why | How long |
|---|---|---|---|
| Your answer history: which question, right or wrong, and when | On your device only | To show your progress and weak areas | Until you delete the app |
In-app purchases
- Full unlock, a one-time purchase. It removes the free question limit and unlocks the mock tests. Restore purchases is in the About screen.
Payment is handled by the App Store or Google Play. We never see your card details. We receive only what you bought and whether it is active.
Why we use your data (our lawful basis)
| Purpose | Lawful basis |
|---|---|
| Running the app and the purchase | Contract: to provide the service you asked for |
We do not sell your data. We do not use it for advertising. We do not make automated decisions about you that have legal or similar effects.
Service providers
We use these companies to run the app. They may only use your data to provide their service to us.
| Provider | What they do | Location |
|---|---|---|
| Apple App Store | Takes payment for the full unlock | Apple |
Where a provider processes data outside the UK, we rely on UK adequacy regulations (for example for the EU), or on the UK International Data Transfer Agreement or the UK Addendum to the EU Standard Contractual Clauses, or the UK-US Data Bridge where the provider is certified.
Deleting your data
- Deleting the app removes your answer history.
Children
The app is for people training to work as door supervisors, who must be 18 or over to get a licence. If you think a child has given us personal data, email us and we will delete it.
Security
Data sent between the app and our providers is encrypted in transit. We give access only to the people and systems that need it, and we keep the amount of data we collect small. No system is perfectly secure. If a breach puts your rights at risk, we will tell you and the Information Commissioner's Office as the law requires.
Your rights
Under UK data protection law you have the right to:
- ask for a copy of your personal data;
- ask us to correct data that is wrong;
- ask us to delete your data;
- object to, or ask us to limit, how we use your data;
- ask for your data in a format you can move to another service;
- withdraw consent at any time, where we rely on consent.
Email gdpr@xfour.co.uk. We will reply within one month. Much of your data may be only on your device, where we cannot see it.
If you are unhappy with how we handle your data, you can complain to the Information Commissioner's Office (ICO): ico.org.uk/make-a-complaint, telephone 0303 123 1113. We would like the chance to fix it first, so please contact us.
Changes to this policy
When the app changes what it collects, we update this page and the date at the top. If a change is significant, we will also tell you in the app.
Contact
XFour IT Limited, 100 Berkshire Place, C/O KT Wells Ltd, Winnersh Triangle, Wokingham, RG41 5RD, United Kingdom.
Privacy: gdpr@xfour.co.uk · Support: support@xfour.co.uk
Policy based on a review of the app's source code (DoorSupervisor-app, main branch) on 29 October 2026.