Knock your iPhone to unlock your Mac

Knock Software, Inc recently came up with an application(Knock) that unlocks your password protected Mac by knocking your iPhone twice.

All you need to do is to pay $3.99 and pair your iPhone(only for iPhone 4s and above) with your Mac and instead of typing the password again and again on your Mac just knock the iPhone twice and it unlocks your Mac for you. You can download the app for Mac from Knock`s Website for free.