Can I use my own Templates?

Hi
Is it possible to import my own templates into Mobile Joomla and replace the default templates.

You can set any template to be used on mobile version of website.

I am confused by how Mobile Joomla works, does it need to be used with a sub-domain or can I operate everything from my main website and use different templates to be displayed subject to whether the site is being accessed by a desktop user or smartphone user.

I am finding the instruction very difficult to follow, I have viewed the video and whilst it is very good I still cannot seem to get to terms with the set-up process.  Is there a better set of instructions, user manual that I could get hold of, please advise.