To see the screen you seek, start with a brand new, or recently erased, iDevice. The Apps & Data screen is found by first erasing all content on your iDevice, then, from the "Hello" screen that appears, navigating in a certain number of steps until you see Apps & Data at the top of a screen with a blue/green icon.
Settings → Cellular → You see the on/off switch for each app under the "Cellular Data Usage" section. Thanks for your super prompt response! I should have joined this forum days ago. On your iOS device, go to Settings > General > Software Update.
How to Access Application Data on the iPhone
That's /data/app/your_package_name for most apps. Some encrypted apps use /data/app-private/your_package_name. This section of your device storage is also known as Shared Storage, as all your apps put their data here.
All apps (root or not) have a default data directory, which is /data/data/
Application data for apps that you bought via the Mac App Store goes in your ~/Library/Containers directory (this is basically ~/Library/Application Support for sandboxed applications).
You can search it as %appdata% and it'll pop up, or you can look in your C:/Users/(YourName) if you're Windows. That's where you saves are.
To see the cellular data usage for individual System Services, go to Settings > Cellular or Settings > Mobile Data.
Cloud synchronization To sync your data via the cloud, simply go to the Settings menu. Tap Synchronization Settings. Tap to reveal the list of available Sync methods.
How to turn on background data on iPhone
Turn on your new iPhone. If you have an old iPhone running on iOS 11 or above next to the new device, you'll see the Quick Start pop-up. Step 2. Tap Set Up Manually to go to the general Apps & Data screen.
On your iOS device, go to Settings > General > Software Update. Make sure you have a recent backup to restore from. Go to Settings > General > Reset, then tap “Erase all content and settings.” From the apps Apps & Data screen, tap Restore from iCloud Backup, then sign in to iCloud.