To use this feature, just start conversations as normal in the Messages app on any of your devices. You can also start a conversation by clicking a phone number in Safari, Contacts, Calendar, or other apps that detect phone numbers. All of your incoming and outgoing messages appear on all of your devices.

 

With Instant Hotspot, the Personal Hotspot on your iPhone or iPad (Wi-Fi + Cellular) can provide Internet access to a Mac, iPhone, iPad, or iPod touch without requiring you to enter the password on those devices.