Apple files a patent application for its iconic 'slide to unlock' gesture for the iPhone.The 'slide to unlock' gesture symbolizes Apple's ambition for an easy-to-use and technologically advanced smartphone.The iPhone's 'slide to unlock' gesture was a simple yet innovative solution to the unlocking problem faced by other smartphone manufacturers.The 'slide to unlock' patent served as a metaphor for dragging a bolt back across a door and was eventually replaced by Touch ID and Face ID.