To resolve the issue of the Words of Wonders (WOW) app not opening on your iPhone 8 Plus, you can follow these step-by-step troubleshooting actions:

1. Force Close the App:
- Double press the Home button to view recently used apps.
- Find the Words of Wonders app and swipe it up off the screen to close it.
- Reopen the app to see if it functions properly.

2. Restart Your iPhone:
- Press and hold the power button until the "slide to power off" slider appears.
- Slide to power off your device.
- Once the device is off, press and hold the power button again until the Apple logo appears.
- After restarting, try opening the Words of Wonders app again.

3. Check for App Updates:
- Open the App Store.
- Tap on your profile icon at the top right corner.
- Scroll down to see if Words of Wonders has an available update. If so, tap "Update".

4. Check for iOS Updates:
- Go to Settings > General > Software Update.
- If an update is available, download and install it.
- Restart your iPhone post-update and attempt to open the app again.

5. Reinstall the App:
- Long press the Words of Wonders app icon until options appear.
- Select "Remove App", then confirm by tapping "Delete App".
- Open the App Store, search for Words of Wonders, and reinstall it.

6. Reset Network Settings:
- Go to Settings > General > Reset > Reset Network Settings.
- Enter your passcode if prompted and confirm the reset.
- This won't delete your data but will reset Wi-Fi networks and passwords, so be sure to reconnect afterward.

7. Contact Support:
- If none of the above steps resolve the issue, consider reaching out to WOW support or visiting community forums for additional solutions. You can check for known issues that may require specific fixes.

If the app continues to have problems after following these steps, you might want to watch troubleshooting videos for further guidance on fixing app issues on iPhones - learn more - learn more.