Qubicle 3.1.2 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app was originally developed by Minddesk Software GmbH. The application belongs to Design & Photo Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
Qubicle is a professional voxel editor optimized for the easy creation of 3D models. The basic application offers an entry point for voxel modelling and is addressed to hobbyists and modders. Custom outfits and weapons for moddable voxel games can be designed, creations can be shared and 3D-models can be ordered online. The program can easily be upgraded to a game design tool with available DLC.
You may want to check out more Mac applications, such as Microspot Interiors Pro, eBPMN or Opera SVG Viewer, which might be related to Qubicle.