Privacy Policy

Effective 30 July 2026 · applies to the Gushi apps for iOS, Android and the web at gushi-chinese.online

Gushi is built by an independent developer, not an ad-tech company. The short version: Gushi shows no ads, uses no third-party trackers or analytics SDKs, and never sells or shares your data. The app works offline; a small amount of data is stored online only so your account can follow you between devices.

What Gushi stores, and why

Your email address — only if you create an account. It is your login (Gushi sends a one-time code to it) and is linked to your account. No password is ever stored.
Your learning progress — the characters and words you study, review results, streak, XP and settings. Stored on your device; if you sign in, a copy is kept online so another device can pick it up.
Your display name and optional profile picture — shown on the shared league board to people you share the app with.
Feedback you send — the message you type and, to help fix bugs, an automatic screenshot of the screen you were on when you tapped the feedback button. Nothing is captured until you choose to send.
A random device identifier — an anonymous id (never tied to your hardware) so the league board can tell players apart before they sign in.

That is the whole list. Usage analytics stay on your device and are never transmitted.

The microphone

The speaking exercises listen while you repeat a sentence, so the app can score how close you were. Speech recognition runs through your platform's own service (Apple or Google). Gushi never uploads or keeps your voice recordings — the transcript is scored on your device and discarded.

If you join a class

Nothing below happens unless you join a class yourself. A teacher cannot add you: they give you a code, you enter it in the app, and you are shown this same list before anything is shared.

Your teacher can see

Which days you studied, and for how long — and therefore your streak.
How many cards you reviewed, and how many you got right.
How well you know each character and word, as estimated by the app's memory model. It is read from how your reviews have gone; you are not tested for it.
Your HSK level, how many characters and words you have met, and your XP.
The name you typed when you joined, and your photo if you chose to include it. Both are stored with that class, not with your account.

Your teacher cannot see

Your email address.
Anything you write in the app, and any recording — see “The microphone” above; those never leave your device in the first place.
Your settings, your reminders or your exam results.
Anything at all about you if you have not joined their class.

The other students in the class see your name, your picture, your HSK level and your XP — the same things the League already shows to everyone using Gushi. They do not see what you have practised or how well you know it. Only your teacher sees that.

You can leave at any time, from your profile in the app. Your teacher stops being able to see you immediately, and everything you have learned stays yours — leaving a class removes nothing from your account.

Your teacher may also release a lesson to the class. That puts its words and characters at the front of what the app offers you next. It is not a deadline: nothing is marked due, and you are never told you are behind.

Where data lives

Account data is stored with Supabase, our database provider, protected by row-level security so each account can only ever read its own data — and, if you have joined a class, so that the teachers of that one class can read the part of it listed above and nothing else. Data is transmitted encrypted (HTTPS).

Deleting your account and data

In the app: Profile → Account & sync → Delete account. This permanently removes your account, your email address and the online copy of your progress, immediately.

By email: if you can no longer open the app, write to mail@niklaskirner.com from the address you signed up with and your account and data will be deleted within 30 days.

Progress stored only on your device is removed by deleting the app (or Profile → Reset all progress).

Notifications

Study reminders are optional, scheduled locally on your device, and can be switched off in the Profile at any time. There is no marketing push.

Children

Gushi is a general-audience study app and does not knowingly collect data from children under 13. An account is not required to use the app offline.

Changes & contact

If this policy changes materially, the date above changes with it and the app will point to the new version. Questions, requests, or anything else: mail@niklaskirner.com. Data controller: Niklas Kirner.