This has been bugging me for a while. I use my android mobile more and more nowadays but when I browse my own site, it looks a little bit cramped because it's just the standard desktop theme.
So, off to look around and I found a nice freeware theme for Zen Cart from a company called Picaflor-Azul.com. The theme in question is Responsive Sheffield Blue. These are called responsive themes because they have the ability to react to differing resolutions of different client devices.
Getting a new theme up and running on an existing store can be quite troublesome. I found the best way to do this was to copy the store's database onto my own computer, install ZenCart locally and run a mirror of ECUFix. This way you can get to know the feel of how the site will look and behave. The only downside I experienced was resetting the side boxes (these settings are not readily portable) and getting the payment modules to work (these have to be deleted and reinstalled again).
There remain a few odd issues that need ironing out but I hope it will open up potential customers to me.