Step 1: Install the app
Scan the QR code that matches your phone and where you live. Google Play is not available in mainland China, so Android users there install through Loadly. The iOS app is not published in the China App Store, so iOS users there install through TestFlight.
| Android | iOS | |
|---|---|---|
| Outside China |  |
 |
| Inside China |  |
 |
- Android, outside China: Google Play.
- iOS, outside China: App Store.
- Android, inside China: Loadly (Play Store is unavailable).
- iOS, inside China: TestFlight (the app is not on the China App Store). Install the TestFlight app first, then open the link.
Step 2: Join the study
After installing the app, you either scan this QR code (link) to join the study or use the code inside the app: XWLCY.
