We have already seen Atama bringing Sesame that can automatically lock your Mac. However, now there is a new app called Knock that lets you unlock your Mac by tapping on your iPhone.
Mac and iPhone owners can say goodbye to unlocking their computer with a password, thanks to the new app Knock. Knock allows a Mac to be unlocked just by tapping the back of a paired iPhone. The two devices are connected via Bluetooth Low Energy (LE), allowing a phone to automatically detect when it nears a paired computer. Though the knocking effect can also be achieved by waving an iPhone in the air, Knock suggests just tapping on it through your pants’ pocket, so you never have to pick up the device.
Despite occasional issues, Knock appears to work just fine, picking up on your presence as soon as you approach your computer. Knock also says that passwords are encrypted and won’t be transferred to any computer but yours.
To use Knock, you have to have iPhone 4S and later models and 2011 MacBook Air or newer, 2012 MacBook Pro or new, 2012 iMac or newer, 2011 Mac mini or newer, and the 2013 Mac Pro.
Here’a a video of how Knock works: