Great news, Squarespace customers. The service’s official iPhone app has just received an update that brings support for Retina display. Which means the mobile Squarespace application will look super-sweet on an iPhone 4 handset. The app, which already lets users interact with their own website via Squarespace in a whole load of different ways (listed below), is currently free – but does require a Squarespace account (which costs customers a minimum of $8/month)