Hi there! I see you're having trouble with Qardio Heart Health not working. Could you please share a bit more detail about what exactly isn't working? For example, is the app not opening, not connecting to your device, not measuring properly, or something else? Also, which Qardio device are you using? This information will help me guide you more effectively.

In the meantime, I'll get us started with some common steps that help in many cases:

1. Check Internet Connection: Since your device uses the WebKit browser on Android 10, make sure the phone has a stable internet connection since the app often requires internet for syncing data.

2. App Update: Ensure your Qardio Heart Health app is updated to the latest version from the Google Play Store. Older versions may not work properly.

3. Device Compatibility: Confirm your Qardio device is compatible with Android 10 and the app version installed.

4. Restart Device and App: Try closing the app fully and restarting your phone.

5. Bluetooth Connection: If using a QardioArm or other Bluetooth device, ensure Bluetooth is enabled and the device is paired correctly.

6. Re-Login: Sometimes logging out and back into the app can restore connection to your account and devices.

If you've tried these already, please let me know what steps you've done and what the exact errors or behavior are, and I can help you dive deeper into the issue. Looking forward to your reply so we can get this sorted!