mouseMagnify() is working on Mac as previously reported.
I am aware that as of April 2013 it is not implemented on iOS or Android and not tested on Windows.
In my app, I do not get callbacks on the following platforms: iOS, Android, or Windows (I have not tested on Linux - no multi-touch input device), but mouseMagnify() is working for me on Mac providing a zoom capability.
I am using JUCE v2.0.40.
Is there any update on the status of mouseMagnify() on the other platforms?