Overall the plugin works ok.
I've had issues when trying to include a custom tab. I just have to insert a shortcode for the custom content. But when I do that and click save it deletes half of my shortcode in the entry box.
Might be a easy problem to fix for the developer but I wouldn't know as they don't seem to be responding to any requests for help.
Fair enough, free plugins won't provide the same amount of support as a paid plugin but I've come across loads of free plugins with great support.
Seeing as 'customer' service is paramount these days I have rated the plugin accordingly.