Our website provided a free download of AstroYacker 0.71 for Mac. The program lies within Design & Photo Tools, more precisely Viewers & Editors. This free software for Mac OS X is a product of Jerrabomberra Observatory.
From the developer:
AstroYacker, in technobabble, uses the Quartz Graphics engine through the Cocoa Application Classes to provide high quality quick affine transformations for translations, rotations, flipping and scaling (and, more importantly, all at once). It interfaces to QuickTime and compression components through the Carbon framework, but where possible most processing is done in Cocoa.
You may want to check out more software for Mac, such as QuickShow OSX, Stone Studio or PhotoDesireeExpress, which might be similar to AstroYacker.