How can you use your iPhone with no service or Wi-Fi?

How can you use your iPhone with no service or Wi-Fi?

You could use apps that require neither

You use it like you would if it had service and Wi-Fi. The only difference is you can't download apps, use apps that require an internet connect or call/message people.

You'd essentially have a media player that can take photos and videos and essential apps like alarm clock and a calculator.