With this Unity extension to the editor's 'File' menu, you can take your work from Unity to any COLLADA (.dae format) importing application (such as Apple's Preview, SceneKit or iBook, Google Earth, SketchUp,...), as well as most digital content creation tools (Photoshop, SceneKit, Autodesk Max, Maya, Blender, ...) , or the web (via collada2gltf), or other game engines (threeJS, Turbulenz, bullet physics ...), even back into Unity and of course your own applications. Unity 5.3+: https://www.assetstore.unity3d.com/en/#!/content/40946
