12 New macOS Sierra Features Worth Upgrading For

Auto Unlock with Apple Watch

When you use a Mac with macOS Sierra installed your Apple Watch can automatically log you in without the need to type your password.

You'll need an Apple Watch with Watch OS 3.0 and you'll also need to log in at some time, so this is not a complete password replacement.

With this set up, when you return to your Mac after a short break you can just open the lid to wake it and your Apple Watch will do the hard work of logging you in.