Download the last New Atlantis client and SDK from this URL : tanant.info/newatlantis
Launch the client.
Register if you are new to the app or login if you have already registered before.

Viewer Controls

Content creation

export NA OBJECTS from Unity3D and import them to NewAtlantisApp...

Object creation guidelines

Keep your sub-object elements count to a minimum.
Parent all your sub-object elements to one root GameObject.
Keep your Asset Bundle size small, because every OBJECT needs to be downloaded by every client (even if we now have a cache system). Rule of thumb : less than 10MB is fine.
Create your own folder with your name (real names or fix pseudo are welcome)
Work only in your folder. This will make easier a merge of you work in another project.
Put all your scripts into one namespace.
The new scripts need to be compiled in the Viewer app for your objects to work in the New Atlantis platform (this is because actual scripts are not embedded into the Asset Bundles for several reasons, only references are stored).