Atlas3D allows you to TEXTURE your imported 3Dmeshes with *NGUI Atlas. It also allows you REPAIR lightmapping to get 1 DRAWCALL with as many dynamically textured & lightmapped meshes without static batching.
Unity will do dynamic batching on meshes that have not more than 300 vertices, scale of 1 and the same material.
You can add LIGHTMAPPING with Unity Editor but normally it will break dynamic batching.
With Atlas3D you can REPAIR lightmapping and still have 1 drawcall on dynamic objects.
Skinned meshes are not compatible with Atlas3D because they are not batching at all even with the same material as other objects.
Components were tested on NGUI 3.0.2, 2.6.3, Unity 3.5.7, 4.1.5 & 4.2, PC, Mac, iOS (iphone4s&ipad2), Android (GalaxyS2)