All state-wide geology maps and geophysics images are stored in MBTiles files - a format created by Mapbox. The textual information that is displayed in pop-ups is held within theses files using a UTFGrid system. The maps and images are created using Tilemill fed by layers stored in PostGIS. CartoCSS is used within Tilemill to style the maps.
The Mapbox iOS SDK is used within the NSW Geology Maps app to display the maps.