Hi there! I understand your BURGER KING app is not working on your iPhone with iOS 18.7. Could you tell me a bit more about what's happening? For example, does the app not open at all, freeze on a loading screen, or do you experience issues logging in? This will help me pinpoint the best solution for you.

While you provide that, here are some initial steps that often help with app problems on iPhones:

1. Force close the BURGER KING app:
- On iPhones with iOS 18, swipe up from the bottom and pause to see recently used apps.
- Find the BURGER KING app and swipe it up to close it.

2. Restart your iPhone:
- Hold the side button and one of the volume buttons until the power off slider appears.
- Slide to power off, then press the side button again to turn it back on.

3. Check for app updates:
- Open the App Store, tap your profile icon, and scroll to see if BURGER KING app updates are available. Install if so.

4. Reinstall the app:
- Press and hold the BURGER KING app icon until the menu appears, then tap "Remove App."
- After removing, reinstall it from the App Store.

If you've already tried these, let me know, and we can try some advanced troubleshooting like checking your network settings, app permissions, or ensuring no server outages are affecting the app.

Are you able to share any details about what exactly “funktioniert nicht” means in your case for the app? That will help me help you better!