Crux Monographic History
Privacy Notice
In short
CRUX is a history reading app run by one person. We hold as little about you as we can get away with: an account identifier, your email address, and a record of what you have read so the app can show you your bookmarks, keep your place in an article, and suggest what to read next. We also keep a simple record of how the app is used, so we can see which articles are read and what to write next.
We do not sell your data. We do not advertise. We do not share your reading with anyone. You can delete everything we hold, from inside the app, at any time.
The rest of this page explains that properly.
Who we are
CRUX Monographic History is operated by Robert O'Sullivan, trading as CRUX Monographic History. Under UK data protection law we are the "data controller" for the information described here, which means we are the ones responsible for it.
You can contact us about anything on this page at feedback@cruxhistory.com.
We are registered with the Information Commissioner's Office (the UK's data protection regulator) under registration reference ZC207133.
You can read CRUX without an account
During the beta you do not need to sign in to read CRUX. Once the beta ends, you can read one article without signing in; to read more, you will need an account.
Signing in is needed if you want to bookmark something or have your reading progress saved to your account. If you never sign in, we hold no account information about you. We do not know your name or email address. Like any app that connects to the internet, the app and the services we use will still see your device's internet address, and give your device random anonymous install identifiers (see 'Who else touches your data').
What we collect, and why
If you sign in
CRUX uses Sign in with Google and Sign in with Apple. There is no password to create and no registration form to fill in. When you sign in, we receive two things:
An account identifier. A long string of characters that identifies your account to our systems. It is not your name and it means nothing outside CRUX.
Your email address. We ask Google and Apple for your email address and nothing else. We deliberately do not request your name or your profile photo, because nothing in CRUX displays either.
We use your email address for one purpose: identifying your account and, if you subscribe, matching a purchase back to you if something goes wrong with it. If you contact Apple, Google or us about a billing problem, your email address is how your purchase gets matched back to your account. We do not send you marketing. We do not add you to a mailing list.
Your email address is stored in the authentication system and in a copy on your account's profile record. Both are deleted when you delete your account.
If you sign in with Google, the email address on your sign-in record refreshes each time you sign in, so it stays current. The copy on your profile is written when you first sign up. If you sign in with Apple, your email address is captured once when you first sign in.
What you read
To make the app work, CRUX records:
- which articles you have bookmarked
- how far through an article you have read
- which articles you have opened and completed, which reading format you used, and when you switched between formats
- a record each time an article or podcast is accessed (your account identifier, the article, the format and the time), which lets us apply any free-reading limit
This is a record of how CRUX is used. It stays inside CRUX and is not shared. It tells us in aggregate which articles people are reading and lets the app keep your place.
Suggested reading
CRUX also uses your reading history to suggest articles and collections you might want to read next. If you have been reading about the Napoleonic Wars, the app will put related pieces in front of you rather than a random selection.
That means CRUX does form a picture of what interests you, within the app. We would rather say so plainly than describe it as something else.
Two things are worth knowing about how this works:
- The suggestions are drawn only from what you have read in CRUX. We do not combine it with anything from outside the app, and there is nothing to combine it with, because we hold nothing else about you.
- It affects what CRUX recommends, and nothing more. It has no bearing on what you pay, what you are allowed to read, or how you are treated.
If you would rather not see personalised suggestions, email us at feedback@cruxhistory.com and we will switch them off for your account. You will get general recommendations instead, and nothing else about the app will change.
What we do not do with any of it
We do not use your reading to target you with advertising, we do not share it with anyone, and we do not sell it. It is deleted in full from our database when you delete your account.
If you subscribe
CRUX may offer a paid subscription. All payments are handled entirely by Apple and Google through their own payment systems.
We never see your card details, your billing address, or any payment credentials. Those go to Apple or Google, not to us. We could not access them if we wanted to.
We use a service called RevenueCat to tell us whether your subscription is active. It reads the purchase receipt from Apple or Google and reports back a yes or a no. No money passes through it, and it receives your account identifier so it knows which subscription belongs to which account. RevenueCat starts when you open the app, before you sign in, and gives your device a random anonymous identifier. If you sign in, it is linked to your account identifier.
If something goes wrong in the app
We use a service called Sentry to tell us when the app crashes, so we can fix it. A crash report contains technical information about what the app was doing when it failed — the screen, the error, the line of code.
Crash reports include your account identifier, so that we can see when the same person is hitting the same fault repeatedly. Your email address is removed before the report is sent.
Sentry also receives non-crash error warnings, podcast playback details (such as your position and whether it is buffering), a short trail of recent taps and network requests, and your device type and operating system version. All of it is linked to your account identifier once you have signed in, and your email address is removed. Reports from people who are not signed in carry no account identifier.
What we do not collect
To be explicit, CRUX does not collect or hold:
- your name
- your postal address
- your phone number
- your date of birth
- your payment card details
- your location
- any advertising or tracking identifier
We do not use advertising networks, we do not track you across other apps or websites, and we have no third-party analytics service watching your behaviour. We keep our own simple record of how the app is used, described above. When the app connects, the services we use see your device's internet address, which can indicate roughly where you are. We do not use it to work out your location.
Our legal basis for holding this
UK data protection law requires us to have a specific reason for processing your information. Ours are:
Performance of a contract. We need your account identifier and your subscription status in order to give you the service you have signed up for. Without them, we cannot let you into the app or know whether you have paid.
Legitimate interests. Crash reports and reading records are held because we have a genuine interest in the app working properly, in knowing which articles are worth writing, and in recommending things you are likely to want to read.
We have weighed this against your own interests. The reading data stays inside CRUX, is never combined with anything from elsewhere, and is used to recommend articles, to see in aggregate which articles are read, and to apply any free-reading limit. It is not used to advertise to you or to price differently for you. We think a reader would expect a reading app to remember what they have read and suggest more of it. If you disagree, you can object, and we will turn the suggestions off for your account.
Legal obligation. We keep certain records where the law requires it, for example for tax purposes.
Who else touches your data
We are one person, so CRUX relies on a small number of established service providers. Each one is bound by a contract that permits them to use your data only to provide their service to us, and never for their own purposes.
| Provider | What they do | What they hold |
|---|---|---|
| Supabase | Our database, sign-in system and file storage | Account identifier, email address, bookmarks, reading progress, reading and access records, usage events, your settings |
| Sentry | Crash reporting | Account identifier and the technical detail described above. Email removed |
| RevenueCat | Subscription status | Account identifier, an anonymous app identifier, and subscription state |
| Apple | Sign in with Apple, and all payments on iOS | Governed by Apple's own privacy policy |
| Sign in with Google, and all payments on Android | Governed by Google's own privacy policy | |
| Expo | Builds and delivers app updates | A random install identifier and your device's internet address when the app checks for updates. Not linked to your account |
| GitHub | Hosts the CRUX website | No personal data |
Our Supabase database and our Sentry account are both hosted in the European Union. Where data is transferred outside the UK, it is protected by the safeguards required under UK data protection law, such as standard contractual clauses.
We will never sell your data. We will never share it with advertisers or data brokers. The only circumstance in which we would disclose your information to anyone else is if we were legally required to.
How long we keep it
We keep your information for as long as your account exists. Records of articles opened by people who are not signed in are not linked to any person, and are kept without a time limit.
There is no fixed expiry date and we will not quietly delete an inactive account — if you come back to CRUX in three years, your bookmarks will still be there.
Your data is removed in two circumstances:
You delete your account. Everything we hold in our own database goes immediately. See below.
CRUX shuts down. If the app is permanently withdrawn, we will give at least 60 days' notice and then delete all user data. Nothing is retained, sold, or transferred to anyone else.
Deleting your account
You can delete your account from inside the app, under Profile. You do not need to email us or ask permission.
If you can no longer use the app, email feedback@cruxhistory.com from the address on your account and we will delete your CRUX account and the data we hold in our own database.
When you do, the following happens automatically:
- Your bookmarks, reading progress and reading records are deleted from our database
- Your usage events and access records are deleted
- Any files associated with your account are removed from storage
- Your account record, including your email address, is erased from the authentication system
- You are signed out of RevenueCat on your device
- You are signed out
Two of our providers keep a separate record that we cannot delete from inside the app. RevenueCat keeps a customer record under your account identifier, which holds no name or email address, and Sentry keeps past error reports until its retention period ends. If you would like these removed sooner, email feedback@cruxhistory.com and we will ask them to delete them.
This is permanent and cannot be undone. If you sign in again afterwards, you get a brand new account with nothing in it.
One thing we cannot delete for you: if you have an active subscription, you must also cancel it through your Apple or Google account settings, because that is where the billing relationship sits. Deleting your CRUX account stops us from providing the service, but only Apple or Google can stop the payment. There are instructions in the app.
Your rights
Under UK data protection law you have the right to:
- be told what we hold about you — which is what this page is for
- get a copy of your data
- have mistakes corrected
- have your data deleted — the in-app deletion above removes everything we hold in our own database, and the 'Deleting your account' section explains how to ask for the rest
- restrict what we do with it
- object to processing we carry out under legitimate interests
- take your data elsewhere in a portable format
- not be subject to automated decisions that significantly affect you — CRUX makes none. Suggested reading is chosen automatically, but it only changes what is recommended to you, and you can ask us to switch it off
To exercise any of these, email feedback@cruxhistory.com. We will respond within one month. There is no charge.
If you are unhappy with how we have handled your information, you can complain to the Information Commissioner's Office at ico.org.uk or on 0303 123 1113. We would rather you came to us first so we can put it right, but you are not obliged to.
Children
CRUX is not intended for children under 13, and you should not create an account if you are under 13.
The app contains serious historical subject matter, some of which covers war, violence and other difficult material. It is written for adults and older readers.
If we become aware that we hold data belonging to a child under 13, we will delete it.
The CRUX website
The CRUX website exists to tell you about the app and to host this policy and our Terms of Service.
It uses no tracking cookies, no advertising, and no analytics. We do not know who visits it.
Security
Access to our database is controlled at the database level, so that your bookmarks and reading progress are visible only to your own account. Credentials are held in secure storage rather than written into the app.
No system is perfectly secure, and it would be dishonest to claim otherwise. If a breach occurred that put your information at risk, we would report it to the Information Commissioner's Office within 72 hours of discovering it, and we would tell you directly if there were a serious risk to you.
Changes to this policy
If we change how we handle your data, we will update this page and change the date at the top. If the change is significant, we will tell you in the app rather than expecting you to notice.
Contact
feedback@cruxhistory.com
Robert O'Sullivan, trading as CRUX Monographic History ICO registration: ZC207133