Courently we are using a Drag and Drop Solution to upload Custom Themes to Ghosted, but why do we not use Dropbox instead?
In one of the next Major Updates we'll include the Option to upload Themes via Dropbox. This will allow you to develope and upload Themes easier and faster because you don't have to zip it before ;)
We finished DropBox Sync testing and are ready to sattle. We will implement DropBox Auth in the next sheduled Update and then provide the Sync Function.