Sparrow, a brilliant email client for Mac, has received a new update to aid compatibility with the upcoming OS X Mountain Lion. The Sparrow 1.6.2 update brings the high-res retina display graphics for the new Retina MacBook Pro. In regards to Mountain Lion, the email client will now be completely ready for the new version of OS X, with compatibility for Notification Centre, allowing for push notifications in the top-right corner of the screen. In addition to this, Sparrow is now on sale for half price, at $4.99 until the 16th of July. You can purchase or update Sparrow through the Mac App Store here.