ijmccallum

This theme demo / theme switcher plugin will add a bar to the top of your WordPress site listing every theme you have installed. It gives visitors the ability to switch between themes and try out their look on your live site.
After installation it requires no set up, it just works.
If you would like to see any extensions to this theme switcher please don’t hesitate to contact me from my website or post something in the support section. And, if you like it – please leave something nice in the review section! The more popular this becomes the more likely I’ll be to work on giving it lots more extra awesome.
<h4>Why another theme switcher?</h4>
I built this theme switcher primarily for myself. There are a number of other theme switchers out there but they all require visitors to click on a drop down menu then select a theme to demo or have some other complication and none of them had the clean, simple, minimal way of switching that I was hoping for in a theme switcher. So I built this theme switcher to give visitors an instant list of all the themes I hope to develop which they will be able to demo in a single click, also it doesn’t need any set up so it’s very easy!
So, I imagine most of the people interested in this theme switcher would be theme developers but if there are any people who are really indecisive about how they want their website to look, I guess this could provide them with an interesting solution to the website design problem. Let me know if you can think of any other uses for a theme switcher!

IJM Theme Switcher Bar

Add a theme switcher / theme demo bar to your site. Allows users to switch the theme they see on your site.

Josh Pollock

Use this plugin to create a demo site for your themes, or use it to allow users to customize the presentation of your site.
The JP Theme Bar Plugin adds a theme switching bar to the bottom of your site, perfect for theme preview sites. The settings page for the plugin lets the end user choose which themes to add, as well as set the colors for the theme bar. You can see it in action on this site.
New in version 0.0.3 -> Themes will update theme mods when changing themes allowing for individual theme settings to be previewed properly.
This plugin is based on the <a href="http://iainjmccallum.com/wordpress/live-demo-theme-bar/" rel="nofollow ugc">IJM Theme Switcher Bar v2.0</a> by <a href="http://www.iainjmccallum.com/" rel="nofollow ugc">Iain J McCallum</a>
IMPORTANT- The plugin <a href="https://wordpress.org/plugins/theme-test-drive/" rel="ugc">Theme Test Drive</a> by <a href="http://www.prelovac.com/vladimir/" rel="nofollow ugc">Vladimir Prelovac</a> must be installed and activated in order for the theme switching to work.

JP Theme Switcher Bar

Adds a theme switcher/ theme demo bar to the bottom of your site to allow users to switch the theme they see on your site.

IJM Theme Switcher Bar vs JP Theme Switcher Bar