A tweet from Second Gear software designer Justin Williams has revealed that Safari engineer Mike Thole has left Apple to join Square, the mobile-payment company who recently brought their innovative credit-card reader to Apple retail stores and other outlets as an alternative to traditional card readers, BusinessInsider reports. Thole, who has not yet updated his LinkedIn profile to reflect the change, listed his duties as working primarily on the user interface of Safari for the Mac as well as the iOS version.