If the LemFi app keeps crashing and prompts you to install WebView, follow these detailed steps to resolve the issue:

1. Update Android System WebView:
- Open the Google Play Store on your device.
- Search for Android System WebView.
- If an update is available, click on Update. This ensures that the WebView is running the latest version, which is necessary for app compatibility.

2. Install or Update Google Chrome (if applicable):
- In the Google Play Store, search for Google Chrome.
- Similar to the previous step, update Chrome if it’s not up to date. Google Chrome often works in conjunction with Android System WebView.

3. Clear Cache and Data of WebView:
- Go to your device’s Settings.
- Navigate to Apps or Application Manager.
- Scroll down and find Android System WebView and tap on it.
- Tap on Storage, then select Clear Cache and Clear Data. This process helps to eliminate any corrupted files that may be causing issues.

4. Reboot Your Device:
- Once you have updated and cleared cache and data, reboot your device. This action refreshes all system operations.

5. Check Compatibility of LemFi App:
- Make sure that the version of the LemFi app on your device is compatible with the current version of Android and WebView. If it’s not, consider uninstalling the app and then reinstalling it from the Google Play Store.

6. Factory Reset (as a last resort):
- If the problem persists, some users found success by performing a factory reset on their device after ensuring all updates were installed. Before proceeding with this step, back up your important data.
- To perform a factory reset, go to Settings > System > Reset options > Erase all data (factory reset). Follow the on-screen instructions to complete the reset.

7. Seek Further Assistance:
- If you have followed all these steps and still face issues, consider reaching out to LemFi’s support or checking forums for any app-specific solutions or updates.

By following these steps, you should be able to resolve issues related to the crashing of the LemFi app due to WebView. For more visual guidance, you can refer to resources like this video tutorial - learn more - learn more - learn more.