If I may,
Expecting for someone to build a suite of free mobile compatible templates is not something I would wait for. If you spend a little bit of time doing some research you'll find a variety of either mobile templates, mobile apps and or responsive web design themes available. As opposed to a desktop theme which can be easily built by modifying the stylesheet, a mobile and/or responsive theme done right requires a large amount of modification to a large amount of files.
I'm very familiar with Zen Cart, not from the functional perspective like several good zenners that know how to write php code like "That Software Guy" but rather from the template design perspective. I guess you can say I know how to paint the vehicle, but leave the engine problems to the mechanics.
A mobile design in my opinion requires learning how to use any of many frameworks available such as bootstrap, zurb, skeleton, jgMobi, jQuery Mobile, Sencha, jQtouch etc... and it is really time consuming.
I could build a desktop template in a couple of hours using the stylesheet and adding several jQuery plugins to make the home page or the product page fancier than an ecommerce site should be however, when it comes to building a mobile theme, hours can turn into months.
The few mobile themes I've seen costs quite a bit however, I would prefer a theme rather than a service such as a couple I have seen. There is also an app in the Apple's app store available. The problem of having an app as opposed to a mobile website is the fact that not only each app has to be written for each mobile device, but also every time the device has an update, chances are the app may have to be updated as well or it will crash.
A mobile site has a lot more flexibility since the owner is in control of updating the files and one site will display "hopefully" properly on all mobile devices.
I prefer building themes with jQuery Mobile. It is the most popular and it is easy to learn. The only issue is that jQuery Mobile loads pages using Ajax and sometimes if not careful some of the scripts designed for Zen Cart to function will not work therefore nreaking your store. This is due to some of the scripts being loaded on a page by page basis instead of using the template override. For example, lets say that a user visits the advanced search page. Under includes > modules > pages > advanced search there is a jscript_main.php file that will load some javascript that will may or may not conflict with jQuery and jQuery Mobile depending on the order in which the files are loaded.
In addition to that, updating a theme already built to a newer version of jQuery Mobile requires some scrutiny to make sure all the files/pages work properly. I'm currently updating my mobile theme and the first problem I found was that jQuery Mobile dropped support for <input type="image" /> therefore destroyin all my buttons.
If you want to create a responsive theme, I would suggest using Bootstrap. It is really easy to learn and to be honest, the most important factor that anyone should take care of when making a mobile version of their site lies in the tpl_main_page.php inside the common folder. As you know, Zen Cart is designed using a table of three columns. Make that table responsive along with the sideboxes collapsible and you are half way there.
I built a Bootstrap theme couple of months ago and it took me some time to actually getting it to validate (W3C) it error free only to learn from Dr. Byte that I can not offer the theme along with the Bootstrap files due to a difference in licenses (See Post: jQuery Mobile for ZC review?).
I did it again. Was only going to say few words and kept on going... I may add this to my blog.:cool: