Low Data Option for Data-Conscious Users
Some of us (myself included) still operate on a data plan, so we often need to limit data-heavy apps or activities and also track our data usage. iOS 13 is now giving us an additional hand: Low Data mode.
You can toggle on Low Data mode located in Settings > Cellular > Cellular Data Options.
Apple recently released the iOS 13 public beta and will be working out some of the kinks to offer better performance and stability as time goes on. The final version of iOS 13 is scheduled for release in the fall of 2019