To address the issue of the Karta GPS app crashing on startup after purchasing the Speed Camera addon, follow these comprehensive steps:

1. Force Quit the App:
- Double-press the Home button (or swipe up from the bottom of the screen on newer models) to view recent apps.
- Swipe up on the Karta GPS app to close it.

2. Restart Your iPhone:
- Press and hold the Power button until you see the slider.
- Slide to power off your iPhone. Wait a few moments, then press the Power button again to turn it back on.

3. Clear App Cache & Data:
- Go to your iPhone's Settings.
- Scroll down and find the Karta GPS app.
- Tap on it and look for options to clear cache or stored data. If there’s an option to reset or clear cache, select it.

4. Update the App:
- Open the App Store.
- Tap on your profile icon at the top right corner.
- Scroll down to see if Karta GPS has any pending updates. If it does, tap Update.

5. Reinstall the App:
- Uninstall the app by pressing and holding the Karta GPS icon until it starts to shake, then tap the ‘X’ to delete it.
- Reinstall it from the App Store. This action helps to eliminate any corrupted files.

6. Check for System Updates:
- Go to Settings > General > Software Update and ensure your iPhone is running the latest iOS version.

7. Contact Support:
- If the app still crashes, consider reaching out to Karta GPS support for specific troubleshooting related to the Speed Camera addon.

These steps are designed to help mitigate the crashing issue effectively - learn more - learn more - learn more.