goxel 0.10.5 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 is an intellectual property of Noctua Software Limited. The software is included in Design & Photo Tools. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
Goxel is a 3D voxel editor that lets you create voxel graphics. The application features 24 bits RGB colors, unlimited scene size, unlimited undo buffer, multiple layers support, marching cube rendering and procedural rendering. The iPad version is free, but there is an In App Purchase to be able to save or export the models.
You may want to check out more software for Mac, such as formZ RenderZone Plus, FRS Coloring Book Volume 2 or FbxConverter, which might be similar to goxel.