A. If the app closes unexpectedly, first ensure that your iPhone's operating system is up to date. Go to 'Settings' > 'General' > 'Software Update' to check for updates. Keeping your device updated can resolve compatibility issues.

B. If the problem persists, try clearing the app's cache. You can do this by going to the app settings and looking for an option to clear cache or data. If that option is not available, uninstalling and reinstalling the app can also help.