Apple just gave owners of older iPhones 4 great reasons not to upgrade to a new device

Federighi said Apple is packaging apps differently in the App Store, which will make them 50% smaller. That also means that apps will download faster, too, as there's less to download.

It's sometimes not the app's storage needs you need to worry about when you first download one — it's the updates that come after you've downloaded the app that can build up over time and take up a bunch of storage space on your iPhone.

Federighi said that updates will be 60% smaller in iOS 13, which should help reduce the amount of storage that apps use up over time.

That's not to say that an iPhone 7 running on iOS 13 will open apps as quickly as the iPhone XS. But Apple is suggesting that apps on an iPhone 7 running iOS 13 will open twice as quickly as they did on the same iPhone 7 running iOS 12.

This is a pretty significant upgrade, as it'll make your iPhone feel faster, and you might not feel like you need to buy a new iPhone if you think your current one is getting slow. It'll hopefully breathe new life into an older iPhone like the iPhone 6S, which will support iOS 13.

It costs $80 to get an iPhone battery replaced at an Apple Store, which clearly poses much better value than buying a new iPhone.

If you have the iPhone 6S or newer, you might do well to get your battery replaced and wait for the new iOS 13 that's rolling out in the fall before making a call on buying a new iPhone.