When trying to run Ground Plane on an iPhone using the front facing camera, it does not work.
In xcode an error message appears saying that ARKit has failed because the appropriate sensor is not enabled.
Since ARKit only works when using the iPhone's rear camera, it's surprising that it's still trying to use ARKit when the front facing camera is accessed. Vuforia allows the selection between front and rear cameras in the configuration file, so when the front camera is selected it should be straightforward for the SDK to use the Vuforia's custom ground plane tracker as opposed to ARKit. It seems like something is missing?