Mandarin Lens ("we", "our", or "us") is a Chrome extension and an iPhone app that generate Mandarin audio and subtitles for YouTube videos and help you remember the words you meet. This policy explains what data we collect and how we use it.
Account information
When you sign in with Google, we receive your email address and a unique user ID from Google. When you sign in with Apple, we receive a unique user ID from Apple and the email address you choose to share; if you choose Apple's "Hide My Email", that is a private relay address that forwards to you, and we never see your real email. We use this solely to manage your account and enforce usage limits.
Usage data
We log when you use the translation and text-to-speech features (action type and timestamp). We use this to enforce usage limits and to understand how the product is used (for example, which screens are opened, whether a word was saved, whether you finished the in-app tour, and whether you tapped Share). These events are tied to your account ID, not your email. The picture you can share of your progress is created on your phone; we never receive it.
Your setup answers (iPhone app)
The name you enter, your learning goals, level, daily time, topics, and roughly how much YouTube you watch each day, and how you heard about the app (optional). We use these to personalize the app (for example, default settings and reminder wording).
Saved words and review progress (iPhone app)
The words you save, the example sentences and the video and moment they came from, and your flashcard review schedule. This lets your words sync across your devices.
Saved videos and clips (iPhone app)
When you bookmark a video or a clip, we store its YouTube video ID and title so your Saved list syncs across your devices.
Watch time and watch log (iPhone app)
We count the minutes you watch videos inside the app with the Mandarin voice on. We also keep a log of which video (its YouTube video ID) you watched and for how many seconds each day. We use this to show your progress and milestones, and to build recaps of what you watched. You can delete this log at any time from Account, then "Clear watch history".
Notifications (iPhone app)
If you turn on daily reminders, they are scheduled on your phone. Your reminder time and style stay on your device.
If you use "Send feedback" in the app, we receive your message, the category you chose, the email you choose to give us for a reply, your app version and device model, and your account ID. We read these to improve the product and reply to you.
If you report a problem with a clip (Clips, then About this clip, then "Report a problem"), we also receive which clip it was (its video and the creator), the reason you chose, and any note you add. A reported clip is also hidden from your own feed, and that choice is stored on your phone.
To provide our service, your data passes through:
Mandarin Lens uses YouTube API Services. Videos and clips play in YouTube's own embedded player, and when you watch, YouTube and Google may collect and use data under the Google Privacy Policy. You can review and revoke the access you have given to apps through your Google security settings. By using Mandarin Lens you also agree to the YouTube Terms of Service.
Usage logs, saved words, your profile and your watch log are kept until you delete your account (you can also delete your watch log on its own). In the app, Account, "Clear watch history" deletes the watch log.
In the iPhone app, go to Account and tap "Delete account". This immediately and permanently deletes your account and the data tied to it: your profile and setup answers, saved words and review progress, watch time and watch log, usage and event records, and your sign-in. If you signed in with Apple, we also ask Apple to end the link between your Apple ID and Mandarin Lens, and you will be asked to confirm with Apple once more. If you also subscribed on the web, that subscription is cancelled. Subscriptions bought through the App Store are managed by Apple, so cancel those in your device's Settings, under your name, then Subscriptions; deleting your account does not cancel them. Payment records held by Apple or Stripe are kept by them under their own policies. If you use the Chrome extension, or cannot open the app, email hello.mandarinlens@gmail.com and we will delete your account and data.
Mandarin Lens is not directed at children under 13. We do not knowingly collect data from children under 13.
We may update this policy as the product evolves. We will update the "Last updated" date at the top when we do.