Henge Docks' Gravitas Dock with Lightning Connector ($89) is one of a handful of products that's just now shipping, a year after it was first introduced at the 2013 CES. Made of a metal alloy that's supposedly 265% denser than aluminum, the dock is a truncated cylinder weighing over 2.5 pounds. A Lightning plug is permanently affixed, and four black plastic inserts are included to properly hold different iPads and iPhones. A USB-to-USB cable is included…