Any 3D modelling software that is capable of producing STL files or files capable of being converted to STL files.
Many of these modelling softwares are available for free download.
Once you have a 3D model design, it needs to be converted into printing instructions for your THREEDY 3D printer. This is done by “slicing” the model into horizontal layers (slices) – so that the object can be built from the bottom up.
Slicing software takes STL files and generates G-code for your THREEDY 3D Printer. Suitable slicing software includes Cura, Slic3r, KISSlicer and all other RepRap 5d firmware compatible slicers eg Repetier, Skeinforge, Simplify3D