To resolve the issue of an app crashing when trying to add a photo, follow these step-by-step strategies:

1. Force Restart Your Device:
- Press and hold the Power button and the Home button simultaneously until the device restarts and the Apple logo appears. This can help clear temporary glitches that might be causing the app to crash - learn more.

2. Update the App:
- Check if there is an update available for the app. To do this, open the App Store, tap on your profile picture in the top right, and scroll down to see if the app is listed under updates. If it is, tap Update.

3. Check for iOS Updates:
- Go to Settings > General > Software Update. If there's a new version of iOS available, download and install it, as updates may fix compatibility issues with apps.

4. Clear App Cache (if applicable):
- Some apps allow you to clear their cache. Navigate to Settings > [App Name] to check for an option to clear cache or data.

5. Reinstall the App:
- Delete the app by pressing and holding its icon until the option to delete appears. After deletion, go to the App Store and reinstall the app. This can clear any corrupted files.

6. Free Up Storage Space:
- Ensure that your device has sufficient storage available. Go to Settings > General > iPhone Storage and check if your storage is running low. If necessary, delete unnecessary apps, photos, or videos to free up space.

7. Check Privacy Settings:
- Ensure that the app has proper permissions to access the camera and photos. Go to Settings > Privacy > Photos and check the settings for the app. Make sure it is allowed to access photos.

8. Reset All Settings (last resort):
- If none of the above solutions work, you may want to reset all settings. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings. This won't delete your data but will reset system preferences.

9. Consult Community Forums:
- If the problem persists, consider visiting community forums such as Apple Support Community or Reddit to see if other users have reported similar issues and found solutions - learn more.

By carefully following these steps, you should be able to identify the cause of the crashes when adding photos and implement a suitable solution.

The app crashes as soon as you try to add a photo.