You are not buying this theme. This is only a preview for Widget Ninja WordPress plugin which functions exactly the same on all themes.

Will this plugin slow my site down?

No. The plugin simply checks the defined conditional tags for each widget that uses Ninja and it either displays it or not.

Will it work on my theme?

Absolutely! Widget Ninja is 100% compatible with all themes.

Can I control any widget? Custom or built in?

Yes, any widget can be controlled by Ninja. It doesn’t matter if it custom or built-in.

What WordPress version does Widget Ninja require?

Widget Ninja requires at least WordPress 3.1 to work properly. It works on 3.0 but you wont be able to define custom options for some tags.

I don’t see Ninja’s GUI on widget xyz

Widget Ninja can only control widgets that use Widget API and not the ones that use deprecated register_sidebar_widget function.