Solved
JavaScript launchSidekick fails when author environment is accessed through a touch device. CQ 5.6.1
In a standard installation of CQ 5.6.1 the sites on the Author environment fails when accessed through a touch device (i.e. iPhone 4). The following error can be observed in the console:
Uncaught TypeError: Cannot read property 'launchSidekick' of undefined
This also happens on the Geometrixx demo sites.