To resolve the issues you are experiencing with the NoiseFit app not opening and your watch not updating, follow these detailed steps:

1. Restart Your Device: Begin by restarting your smartphone. This basic troubleshooting step can help refresh the app and device connections.

2. Clear App Cache and Data:
- Go to Settings on your Android device.
- Select Apps and then find and tap on the NoiseFit app.
- Click on Storage, then tap Clear Cache and Clear Data. This ensures that any corrupted data hindering the app from opening is removed.

3. Check for App Updates:
- Open the Google Play Store.
- Search for NoiseFit and check if any updates are available. If an update is present, tap on Update to install the latest version - learn more.

4. Reinstall the NoiseFit App:
- If the app still does not open, uninstall it by going to Settings > Apps > NoiseFit and tapping Uninstall.
- Once uninstalled, return to the Google Play Store, search for NoiseFit, and download it again.

5. Update Your Watch:
- Open the NoiseFit app once it is reinstalled.
- Navigate to Settings and select your device (such as ColorFit Pulse Grand).
- Click on Check for Update and follow the on-screen instructions to update your watch - learn more.

6. Check Your Network Connection:
- Ensure your smartphone has a stable internet connection.
- If using Wi-Fi, try disconnecting and reconnecting or switching to mobile data.

7. Inspect Permissions:
- Go back to Settings > Apps > NoiseFit.
- Tap on Permissions to verify that the app has all the necessary permissions enabled, especially access to storage and location.

8. Consult Online Resources:
- If the problem persists, you can watch tutorial videos on platforms such as YouTube for additional guidance. There are several resources available that provide step-by-step fixes for common issues - learn more and learn more.

By following these steps, you should be able to troubleshoot the NoiseFit app not opening and update your watch accordingly.