What we agree on.

Who is behind Kerfox, and what these terms cover

Kerfox is run by Kerfox Ltd, a private limited company registered in England and Wales under number 17429118. When these terms say "we", they mean Kerfox Ltd, and that is the company you are agreeing with.

You can reach us at eivan.kolchin@gmail.com, which is the address to use for anything formal as well as anything ordinary. Our registered office is published in the footer of every page of this site, and you can write to us there.

These terms cover the kerfox.app website, the first-batch waitlist, the Kerfox app at kerfox.app/web, and the Android builds we hand out while the app is still on its way to the stores. Our privacy policy sits beside them and explains what happens to anything you send through this website, and the app carries its own privacy notice covering what happens inside it.

The first batch is a test

The first batch is exactly that: an early build, given to people willing to meet Kerfox before it is finished. Please hold it loosely.

• It may break, freeze, or refuse to open after an update.
• It may lose progress. Streaks, mastery and saved work can vanish in a test build, and there is no promise that anything survives to the public release.
• Content may contain errors: a wrong number, a mistyped equation, a figure labelled the wrong way round. Everything ships through automated checks, and checks catch a great deal rather than everything.
• Features may change shape, move, or disappear between builds.
• A test build, or the whole first batch, may be paused, replaced or withdrawn.

So Kerfox is offered as it is, and we do not promise it will be available, uninterrupted or fault free. Keep your own notes for anything you cannot afford to lose, and tell us when something is wrong. The fastest route is the Contact us screen inside the app, which passes your message, your platform, your study level, how many subjects you have picked, how many questions you have answered and any screenshots you attach through our backend host Supabase into a private channel only we read; the email address above is the alternative, and it is the one to use for anything about your own personal data.

A study aid, not an exam board

Kerfox is a study companion. It is not a school, not a tutor, not an awarding body, and not a replacement for your course, your teacher or your specification.

We write A-Level content against the published specifications of AQA, OCR, Edexcel and WJEC, and university content against real modules. Naming a specification tells you which syllabus a lesson was written for, and nothing more. Kerfox is not affiliated with, endorsed by, approved by or connected to AQA, OCR, Edexcel, WJEC, any university, any school or any awarding body, and those names belong to their owners.

We cannot promise a grade, a mark, a pass or any exam outcome, and we will never claim one. What we can say is that the content goes through automated checks before it ships, and that we correct what you tell us is wrong.

Where a lesson touches something beyond study, in biology or chemistry for instance, it is general educational information and not professional advice.

Free, with no bill coming

Kerfox is free. The site, a seat in the first batch, a test build and the app all cost nothing, and nothing in these terms creates a payment obligation for you.

We do not ask for card details, and a free test build will never turn into a charge after the fact.

The app already shows a Pro page with plans and prices on it, and nothing there can be bought: no purchase path is connected, the prices are placeholders, and the only limits Pro lifts today are on the AI feature. If a paid tier does open it will be a separate choice with its own price and its own terms, agreed before anything is charged, and the heart of Kerfox, the lessons, the questions and the memory engine, is meant to stay free.

Support, once it opens, is a gift rather than a purchase. It buys no feature, no seat and no priority, and Kerfox is not a registered charity, so it is not a charitable donation and carries no tax relief.

Your seat is yours

A first-batch seat belongs to the person who asked for it. A first-batch seat is your name on our list, and the builds themselves sit on a public releases page, so we cannot stop a link being passed on and we are asking rather than enforcing. Please send people to the waitlist instead, where a seat also costs nothing.

The app keeps your progress on your own device. An account is optional and adds a backup across devices, nothing else. If you make one, keep the password to yourself and tell us if you think someone else has got into it, and we will treat what happens through your account as yours unless you have told us otherwise.

Install Android builds only from our releases page at github.com/EivanKolchin/Kerfox/releases, which is the only place we publish them.

Using Kerfox fairly

The short version: use it to study, and leave it working for everyone else.

• Use Kerfox for your own study, or for your own teaching if you teach.
• Do not lift the lessons, questions, solutions, figures or artwork out in bulk, by hand or by script, and do not scrape, mirror or republish them.
• Do not sell, rent, sublicense or repackage any part of Kerfox.
• Do not try to break, overload or probe the app, work around its limits, or reverse engineer it beyond what the law allows you to do anyway.
• Do not enter other people’s personal details, and please keep health and other sensitive information out of the free-text boxes.
• Do not use Kerfox to break your school, college or university rules on assessed work. What counts as help and what counts as cheating is set by them, and it stays between you and them.
• Do not use the AI feature to produce anything illegal, hateful, or aimed at harming someone.

What belongs to whom

The lessons, questions, worked solutions, figures, animations, artwork, the fox and the name Kerfox are ours. They were written and drawn for this app, they are protected by copyright, and they stay ours.

While your seat is open we give you a personal, non-exclusive, non-transferable licence to use Kerfox for your own study or teaching on your own devices. The licence ends when your seat does, and it never becomes ownership.

You may keep private copies for your own revision, print pages for yourself, and do anything else UK copyright law already permits, including fair dealing for private study, quotation with acknowledgement, and illustration for instruction, which covers a teacher putting one of our figures in front of a class; nothing here cuts those short. Anything wider, a website, a video, a set handed round beyond your own teaching, needs our agreement first, and we usually say yes when asked, so ask.

What you write stays yours: your notes, your answers and anything you type into the app.

Feedback and ideas

If you tell us Kerfox should do something, or that a question is wrong, or that a screen confused you, we may act on it. We may build what you suggested, keep it, and use it however we like, without payment, credit, confidentiality or any obligation back to you.

That is not us taking your work. It is the only way a bug report or a "you should add" can be used at all. Please do not send anything you need kept secret, and do not send anything that is not yours to send.

The AI feature, and how the app adapts

The app has an optional AI feature that turns notes you paste into practice. What you type is sent to Google, whose Gemini models make the practice, which means it leaves your device and leaves the United Kingdom, and on the free tier Google may keep it and use it to improve their models, so read their terms before you paste anything you would not want kept. If we ever move to a different provider we will say so here and in the app before we do.

The memory engine adapts to you, deciding which ideas come back, when, and how hard. It is a revision schedule and not a judgement about you. It makes no decision with legal or similarly significant effects, and there is no automated decision-making of that kind anywhere in Kerfox.

Your privacy, in short

The privacy policy covers this website, the first-batch signup and the contact form: the site sets no cookies and tracks nothing, the signup form has no server behind it and composes an email in your own mail app, and the contact form sends what you typed to us through the same backend the app uses. The app is a separate matter, and it does send things: it runs on a backend hosted by Supabase, it reports how lessons and questions went so we can see where the app is failing people, an optional account keeps a backup of your progress there, and a message sent from the app’s own contact panel reaches us through that backend. The app’s privacy notice sets all of it out in full, at kerfox.app/app-privacy, and it is published there before any test build asks you to install it.

The insight programme is optional and is never ticked for you. Nothing is recorded under it until a test build asks you again inside the app and you say yes there, and you can withdraw at any time by turning it off in the app or by writing to us at eivan.kolchin@gmail.com. Ticking it is not a condition of a seat and it does not move you up the list.

One email to us takes you off the list, and we then delete the signup and its answers from our mailbox, usually within days and always within a month, though a copy sits in our mail provider’s deleted items for up to 30 days before it goes for good and the copy in your own sent folder stays yours to delete; if you have made an app account or sent us a message from inside the app, say so in the same email and we will delete those too.

If you are under 18

Kerfox is built for students, and a great many of them are at school. You are welcome here.

You should be 13 or over to send the signup yourself, because that is the age at which UK data protection law lets you agree to a service like this on your own; if you are younger, Kerfox is not for you yet, so ask a parent or guardian to sign up in their own name and their own email and to look at the app with you when it arrives. If you are between 13 and 17, please read the insight programme box slowly before you tick it, because it records when and how often you study, which is more than the app needs in order to work, and leaving it unticked costs you nothing.

If you are a parent or a teacher, sign yourself up rather than the person you have in mind. Give your own name and your own email, and not a child’s or a student’s.

What we are responsible for

We take real care with what ships. Every equation is rendered and every question is run through automated checks before a build is allowed out, which catches broken maths and broken questions rather than proving an answer right, and we correct what you report as wrong as quickly as we can.

As far as UK law allows, we are not liable for exam or coursework outcomes, for revision time you feel was wasted, or for any loss that was not a reasonably foreseeable result of something we got wrong; we do not exclude our liability for damage to your device or to your other files where that damage would not have happened had we taken reasonable care, and if a test build causes damage of that kind we will put it right or pay you fair compensation.

Some things cannot be limited and we do not try. We do not exclude liability for death or personal injury caused by our negligence, for fraud or fraudulent misrepresentation, or for anything else UK law does not allow to be excluded. Nothing in these terms takes away rights you have as a consumer, including under the Consumer Rights Act 2015 where it applies, and nothing here asks you to give up your right to go to court.

Where we link somewhere else, to our releases page, our payment pages on Stripe, or an exam board’s own specification, what is on the other side is theirs and not ours.

Leaving, and being asked to leave

You can leave whenever you like. Sending the signup is how you agree to hear from us, and what you will get is short: word when a build is ready, word when something material on this page changes, and very little else. Every message carries an unsubscribe link, and one click on it, a reply saying stop, or a note to eivan.kolchin@gmail.com takes you off the first-batch list.

We may end a test seat or withdraw a build. Normally that is simply the batch closing and everyone moving to the public release, and we will say so in advance. We may also end a seat where it has clearly been shared, sold or automated, or where Kerfox is being used in a way the fair use section rules out. Where it is fair to do so we will tell you why first and give you a chance to put it right.

Ending a seat costs you nothing, because nothing was charged. When a seat ends the licence above ends with it, and the parts of these terms that still make sense afterwards, on ownership, feedback, liability and the law that applies, carry on.

Changes, and the law that applies

These terms will change as Kerfox grows out of testing. The date at the top of this page says when they last did. If a change matters, meaning it affects what you can do or what we can, we will write to first-batch members at the address they signed up with and note it here.

When a change matters we will write to first-batch members at least 14 days before it takes effect, say plainly what has changed and why, and carrying on with Kerfox after that date is how the new terms take effect for you.

These terms are governed by the law of England and Wales, save that if you live in Scotland or Northern Ireland you keep the protection of the mandatory law where you live; you can bring a claim in the courts of England and Wales or in your local courts, and we will only ever bring one in your local courts.

If something has gone wrong, tell us at eivan.kolchin@gmail.com. Our complaints page at kerfox.app/complaint sets out exactly how to raise one, what we will do about it and how long we will take. Where the complaint is about your personal data, section 164A of the Data Protection Act 2018 gives you the right to bring it to us directly, and we will acknowledge it within 30 days, look into it properly, keep you posted while we do, and tell you the outcome without undue delay. You do not have to come to us first: you can complain to the Information Commissioner’s Office whenever you like, at ico.org.uk/make-a-complaint, on 0303 123 1113, or by post to Wycliffe House, Water Lane, Wilmslow, Cheshire SK9 5AF.