Davide Sher wrote about HEXOstudios 1.1 for VoxelMatters. His article walks through the app, the new formats in version 1.1, the HEXO engines behind STEP and Rhino files, and how the app handles very large libraries.
Pointed at a folder, HEXOstudios gives every model a rendered thumbnail card. A downloads folder with hundreds of files becomes a browsable library with nothing moved, renamed, converted, or copied.
A STEP assembly, a Rhino model, and a FreeCAD part can therefore sit side by side in 3D on a Mac with none of the original CAD applications installed.