Privacy

The short version

• No advertising, no ad networks, no data sold or shared for marketing.
• No advertising or analytics scripts, and nothing from a tracking company.
• We keep our own security log of pages opened, for a year. Your address is cut back to your network before it is written down.
• No card details, ever — we do not take payments.
• A child's answers are marked and thrown away. Only the score is kept.
• An account is optional. Most of the site works without one.
• In the phone app, your face or fingerprint never leaves the device.

What we collect

If you create an account

Your email address, the name you choose to display, and your password, which is stored only as a cryptographic hash and is never readable by us. If you sign in with Google or Apple instead, we record which of those you used and the email address they give us; we never see your password for those accounts.

You may optionally tell us your US state, which we use to show the standards that apply where you are. You can leave it blank.

About a child

A parent may add a child to their account. That is a name — a first name or a nickname is plenty, and we would rather you used one — and a school year, so practice can be picked for the right level. We do not ask for a date of birth, a photograph, an address, a school, or anything else about a child, and there is nowhere for a child to give us any of it.

Practice

When an exercise is finished we record which exercise it was, how many questions were right out of how many, and when. We do not keep the answers. Typed answers are sent to our server, marked, and discarded in the same request — they are never written down, which is why we cannot show you what your child typed, only how they did.

If you write to us

The contact form keeps your name, your email address, what you chose the message was about, the message itself, and which page you were on when you opened it. The feedback widget keeps a yes or no, an optional comment, and the page you were on. If you apply for a job, we keep what you put in that form: your name, email address, and optionally a phone number, a link, and your note.

The app on a phone or tablet

The iOS and Android apps do two things the website does not, and both are offered once, just after you create an account. Either can be refused, and refusing neither stops the app working.

Signing in with a face or a fingerprint

If you turn this on, your device is issued a credential that is kept in the phone's own secure storage — the Keychain on iOS, the Keystore on Android — behind the biometric lock. Your face and your fingerprint never leave the device and we never see them. The check happens on the phone; all we receive is the credential it releases, which tells us that this device is allowed in. We can revoke it, and you can too, from your account page — which is what to do if a phone is lost.

Notifications

If you allow notifications, the app registers with Apple or Google and passes us the address they know your device by, so that we can send to it. We keep that address, which device it belongs to, and nothing else. It is used to send you reminders about practice and nothing else — not advertising, and never passed to anybody.

Notifications go to whichever device has the app installed, which may be a device a child uses. You can turn them off in your phone's settings at any time, and removing the device from your account stops them immediately.

What is stored in your browser

We use no cookies. A few things are kept in your browser's own local storage, which never leaves your device and which we cannot read from our side:

• Your sign-in token and the name shown in the corner, so a refresh does not sign you out.
• Light or dark theme.
• Which exercises have been finished, so the tiles can be ticked when signed out.
• A half-finished exercise, so closing the tab does not lose the work.
• Small preferences like the year last chosen on a filter.

Clearing your browser's site data removes all of it. None of it is used to identify you anywhere else.

Our security log

We keep a record of which pages were opened and which parts of our service were called, so that we can answer for what happened on an account — investigate a sign-in that was not yours, work out what went wrong when something breaks, and see abuse when somebody attempts it.

Each entry holds the page or address that was reached, whether anybody was signed in, the time, and the network the request came from rather than the connection. That last part matters: we shorten an address like 203.0.113.47 to 203.0.113.0 before storing it, which is enough to tell one household or school from another but not enough to point at a particular person or device. We do not record what browser you use, which would put that back.

It is ours alone — it is not analytics, nothing is sent to another company, and it is not used to build a profile of anybody or to decide what to show them. Entries are deleted automatically after one year.

Who else is involved

We keep the list of third parties as short as we can manage. Today it is:

• Microsoft Azure — hosts the site and the database. Your data sits there and nowhere else.
• Google reCAPTCHA — used on the contact, feedback and job application forms to keep automated abuse out. Google receives what it needs to make that judgement, under its own privacy policy.
• Google and Apple sign-in — only if you choose to use them, and only to confirm you are who you say you are.
• Apple Push Notification service and Firebase Cloud Messaging — only in the phone apps, and only if you allow notifications. They carry the message to your device; they are not told anything about your child.

There is no advertising network, no analytics provider, and no payment processor. The security log described above is our own and stays with us. We do not sell, rent or trade anybody's information, and we never will — if that ever changes, this page changes first and we will say so.

Children

This site is meant for children from kindergarten to grade 5, so we treat everything about a child as belonging to their parent.

A child cannot create an account. Only a parent can, and only a parent can add a child, see their progress, or remove them. A child using the site can answer questions and read explanations; there is no way for them to publish anything, message anyone, or give us information about themselves.

A parent may ask at any time to see everything we hold about their child, to have it corrected, or to have it deleted. Removing a child from your account removes their progress with them. For anything else, write to us and we will do it.

How long we keep things

Account and progress information is kept while the account exists. Messages, feedback and job applications are kept while they are still useful to answer or act on. Security log entries are deleted automatically after one year. Ask us to delete any of it and we will.

Asking us to delete something

You can remove a child, and their progress, from your account page yourself. For anything else — deleting your whole account, a message you sent, an application you made — write to us and a person will do it by hand. We will confirm when it is done.

Changes

If what we collect changes, this page changes at the same time rather than afterwards. The date at the top is when it was last edited.

Getting in touch

Questions about any of this, or about what we hold on you or your child, go to the contact page. A person reads every message.