Sculpt

Sculpt is a 3D sculpting application that provides an intuitive workflow using a number of powerful modeling tools.  Sculpt allows artists to rapidly create complex meshes.

Main features :

Export file to 3d format: Collada(.dae) , Scenekit(.scn) and STL(.stl) 
Snapshot Image:JPEG,PNG,TIFF
Standard tools : Draw, Crease, Smooth, Grab, Pinch,Flatten, etc
Deletes UV
Triangles only
Operates in real time
Local subdivision (create new triangles)
Local decimation (deletes triangles)
Undo/Redo support