I downloaded the Demo to check out the app. I last used the old PC based one (back before it was commercialized).
The first issue I ran into was with the UI.
Use Case: Add Marker and 3D Object to Scene. Select the 3D Model in Scene.
The Translation, Rotation and Scale input boxes are have just a single field for each. You can tab within the field but it's very user-unfriendly. I would expect the UI to mimic the PC application with separate boxes.
Next the Scale box is not accessible.
See attachment BuildAR_UI.png
Use Case: Add Marker and Select Marker in Scene.
"Remain visible for X milliseconds" is cut off in the UI.
See attachement BuildAR_marker.png
BuildAR v2.2.1
MacOS 10.6.8