The terms, in language you can actually read.

What Cairn is

Cairn is an Android app that reads the text on your screen and explains the word you tap. It is a study aid. It is not a professional translation service, and the explanations are written by a language model, which means they are usually right and occasionally wrong. Do not rely on Cairn for anything where being wrong would matter, such as medical, legal or financial text.

Your account

Cairn creates an anonymous account on first launch so your saved words have somewhere to live. You may sign in with an email address or a Google account to raise the weekly allowance and to sync between devices. You are responsible for keeping access to whatever you sign in with.

One person, one account. Do not use Cairn to run automated lookups, resell access, or work around the allowance by creating accounts in bulk. We may suspend an account that does.

The free tier

The dictionary, readings, audio, on-device translation, saved words, history and sync are free and have no expiry. AI explanations are limited to 20 a week on an anonymous account and 40 a week when signed in. The window resets weekly. An answer served from the shared cache does not count against it.

These numbers may change. If a limit goes down we will say so in the app before it does.

Cairn Pro

Pro costs $3.99 a month or $23.99 a year, converted by Google Play into your local currency with local tax applied. Play shows you the exact amount before you confirm, and that amount is what you pay.

• Subscriptions renew automatically until you cancel.
• Cancel in the Google Play app under Payments and subscriptions. Cancelling stops the next renewal; Pro keeps working until the period you have already paid for ends.
• Refunds are handled by Google Play under Google’s refund policy, not by us. Write to us anyway if something has gone wrong and we will help where we can.
• A feature marked as still being built is exactly that. Nothing on the Pro list that is already working will be moved behind a higher tier.

The accessibility permission

Cairn cannot work without Android’s accessibility permission, which you grant by hand and can revoke at any time in Settings. What the app does with it is set out in the privacy policy. Revoking it stops the tap feature; the rest of the app still opens and your saved words are still there.

What we do not promise

Cairn is provided as it is. We do not promise it will be available without interruption, that the explanations will always be accurate, or that it will keep working with every future version of Android. Android’s rules for accessibility services change, sometimes at short notice, and a change there can affect what the app is allowed to do.

To the extent the law allows, we are not liable for indirect or consequential loss. Nothing here limits liability that cannot legally be limited, and nothing here takes away consumer rights you have where you live.

Content and licences

Your saved words are yours. Cairn’s dictionary data comes from CC-CEDICT, JMdict and Wiktionary, all under CC BY-SA 4.0, and the databases built from them carry the same licence. Japanese analysis uses Kuromoji under Apache 2.0. Translation uses Google ML Kit. The app itself, its name and its design are ours.

Ending it

You can stop using Cairn at any time by uninstalling it, and ask us to delete your account as described in the privacy policy. We may end access to an account that abuses the service or breaks these terms, and where it is reasonable to do so we will say why first.

Changes

If these terms change materially we will say so in the app before the change takes effect. The date at the top of this page is when they were last revised.

Getting in touch

Write to support@cairnapp.fyi. We read everything.