Open sesame! Mac users can use their Watch to Auto Unlock their computer. First, make sure your Mac was purchased in 2013 or later (sorry, owners of older models — this trick only works on newer machines). Also check that your Mac is running the Sierra operating system (or a later version) and that your Watch is running watchOS 3 or later. You’ll also need your iPhone for this, running iOS 9 or later. Also, be logged into all devices on the same iCloud account.
Then, you’ll have to enable two-factor authentication on your iPhone. (Disable two-step verification if you’re using it already.) On your iPhone, go to the Settings app, then the iCloud menu. Tap the name of your account on the next menu, followed by Password & Security. If Two-Factor Authentication is not already On, tap Get Verification Code and type in the code to have access to turn it on. Finally, make sure both your Mac and Watch have a password or passcode for entry.
Once all of that updating is out of the way, you’ll be eligible to magically log into your machine via Watch automatically and remotely. Set up this functionality via System Preferences on your Mac. Navigate to Security & Privacy, and under the General tab, you’ll find a box you can check, “Allow your Apple Watch to unlock your Mac.” Now, whenever you’re sitting in front of your Mac wearing your Watch, your Mac will unlock.
Related: Check Out the Redesigned Apple Watch