3D-View: All colorspaces can be viewed in any other colorspace with 3 channels. Lch, HSV and HSL can additionally be viewed in a cartesian coordinate system.
Metamerics and Illumination: Chromaticity error, Color rendering index, Visible range metameric index and UV range metameric index according to ISO 3664:2009 and ISO 23603:2005 with reference illumination D50, D55, D65 and D75.
Measurement devices: Currently, only the FD-7 measurement device is supported. Remission measurements currently always are based on D50.
Simply write a (friendly) email to email@example.com. Note that German is the preferred choice of correspondance but English is offered as a common language of inter-communication.
Support for Leopard (10.5): The application can not be provided for Leopard at this time. The reason for this are several API-calls which are only available in 10.6 (Snow Leopard). A re-implementation would be necessary, followed by an extended testing-phase.