Privacy Policy — Yayu

Last updated: 30 September 2026

Yayu shows one Chinese word a day. There are no accounts and no sign-in, nothing here is sold, and most of what the app knows about you never leaves your phone.

What the app keeps on your phone

The word list, the dictionary, the typefaces and the pronunciation recordings all ship inside the app, so it works offline. So does everything it learns about you: which words you have seen, which you have hearted, where you are in the trail you have browsed, your reminder time, and your display and filter settings.

None of it is stored anywhere but your phone. There is no account and nothing is synced, so none of these lists is uploaded, and nobody can look up what you have saved. What you type into search is never sent. Deleting the app removes all of it from your phone — though if you later restore a device backup made while the app was installed, it can come back with it, the same way your other apps' data does.

That is about where your data is kept. It is not the same question as what is counted: some of these actions are also counted, and three of those counts name the word involved. Read Usage counts below for what actually leaves the phone — in particular, hearting a word is counted, and the count says which word it was.

What the app sends, and to whom

Usage counts — to us

The app counts how its features are used, so we know what to build, and sends those counts to a server we run on Cloudflare. What is counted: opening the app, moving forward or back through words, opening Settings, hearting a word, sending one to Pleco, exporting, sharing or saving a word card, playing a pronunciation, opening a reminder, what became of the daily-reminder prompt, and whether you allowed or refused notification permission.

For a word card, the count also says what you chose to put on it — whether the pronunciation and the translation were showing, and whether the characters were laid out as a square — and whether you shared it or saved it to your photos. It does not include the picture, and it does not say which word was on it.

Each count carries:

• An install identifier — a random value created the first time the app sends usage counts, and stored on your phone. It identifies an installation, never you. Deleting the app removes it, though restoring a device backup afterwards can bring it back.
• Your platform, device model, OS version and app version.
• Whether you have a subscription, as a plain yes or no, with no purchase details.
• The country the request came from, which our server reads from the connection. Never a city, and never your IP address, which is not recorded.

Three of these counts record which word it was: hearting a word, sending one to Pleco, and exporting a single word. Exporting a list records that a list was exported, not what was in it.

Every word involved comes from the dictionary inside the app, so none of it is anything you wrote — but over time that record is a picture of what you are studying, attached to the identifier for your install. There is no setting that turns this off.

Sending a word to Pleco is only possible if you have Pleco installed, so that count also tells us a Chinese dictionary app is on the phone. The app does not and cannot read the list of apps on your device.

Crash reports — to Sentry

When the app crashes or hits an error, a report goes to Sentry so the fault can be fixed. It carries the error, the trail of events leading to it, and your device model, OS version and app version. Usernames, email addresses and IP addresses are switched off, and the console trail is excluded. Nothing you were reading, searching for or had saved is part of a report.

Alongside reports, the app sends a short record of each time it runs and whether it ended normally or in a crash. Sentry's libraries may attach an identifier for the installation to those records; where it exists it identifies an installation, never you. Sentry's handling of what it receives is covered by their privacy policy.

Install counts — to Expo

Yayu is built with Expo, and a component inside the app reports each cold launch to Expo. It sends its own randomly generated install identifier, the app version, the platform and the OS version — nothing about what you did. See Expo's privacy policy.

Advert requests — to Google

Yayu shows adverts in two places: a card in the feed every few swipes, and a full-screen advert on the way into Favorites. They come from Google AdMob.

• Not straight away. Neither appears to a new reader, and until the first one does, no advert software runs and nothing below leaves your phone.
• On iPhone and iPad the adverts are not personalised, which is why Yayu never asks for permission to track you across other companies' apps and websites.
• In the EEA and the UK you are asked before any advert is requested. You can change your answer under Settings → Your advert choices. Declining limits what Google may use when choosing adverts; it does not switch them off.
• There is no setting that turns adverts off, and no advert-free tier in this release.

To show an advert, the app asks Google for one. That request carries your IP address and a description of your device, and on Android your device's advertising ID, which you can reset or opt out of under Settings → Privacy → Ads. On iPhone and iPad no advertising identifier is sent. Google uses this for its own advertising business rather than on our behalf, so it is covered by Google's privacy policy and their partner-sites notice.

Nothing you read, search for, heart or export is sent to Google, and the app does not tell Google which word you were looking at.

Notifications

If you turn on the daily reminder, your phone schedules it from words already on the device. There is no push server and no push token, and nothing about a reminder leaves the phone.

Sharing a word

Exporting a word list or a card hands a file to your phone's share sheet. Where it goes from there is your choice; Yayu does not upload it anywhere.

Saving a card puts the picture in your own photos instead. Yayu never reads your photo library — it only ever adds a card you asked it to save, on every version of both platforms.

Whether your phone asks you to allow that depends on the phone:

• On iPhone and iPad, you are asked once, and only for permission to add photos. Looking at your library is a separate permission that Yayu does not request and could not use.
• On recent Android versions, you are not asked at all, because adding a picture this way needs no permission.
• On older Android versions, you are asked for a single shared-storage permission that covers adding and reading, because those releases have no narrower one to ask for. The grant is wider than what Yayu does with it, which is still only writing one picture.

The picture is made on your phone from a word the app already carries, and it is not uploaded anywhere either.

What does leave the phone, for a share or a save alike, is the count described under Usage counts above — that it happened, what was on the card, and which of the two you chose. Never the picture, and never the word.

The identifiers

The app's own install identifier, the one Expo sends, any identifier Sentry attaches and Google's advertising ID are separate values held by separate services. We do not join any of them to any other, and none is linked to your name, your email or an account — there are none to link to.

Deleting the app removes the ones kept in its own storage, though a device backup restored afterwards can return them. Your advertising ID is not one of those — it belongs to your phone rather than to Yayu, is shared with every app that asks, and outlives this one. Reset or opt out of it under Settings → Privacy → Ads on Android; on iPhone and iPad Yayu never receives it at all.

What Yayu does not do

• No selling of data to anyone. Apart from Google's part in showing adverts, the services above act for us, on our instructions.
• No advertising identifier on iPhone and iPad, and no tracking anywhere — which is why the app never asks permission to track you.
• No access to your device's location, contacts, microphone or camera, and no reading of your photos — saving a card can add one, and that is all it can do.
• No third-party trackers beyond the advert request described above.

Children

Yayu is not directed at children and does not knowingly collect personal information from anyone, children included.

Changes

If this policy changes, the date at the top changes with it.

Contact

Questions about this policy, or about anything above: Yayu.daily.chinese@gmail.com