Technology enthusiasts are always interested in experiencing new and innovative solutions that make daily life that little bit easier. The majority of us usually carry our phones around with us and the growing popularity of OS X means that more and more people are interacting with Macs on a daily basis. Security is generally high on everyone's agenda when using our static and mobile devices, but where is it written that a secure computer has to be a tedious one? The new Knock app is aiming to put an end to that tedium by letting users unlock their Macs by simply 'knocking' on their iPhone.