JoomlaWorks Simple Image Gallery Pro plugin

Does this mean that I have to purchase the 'Pro' version or is there a downloadable plugin that is free? Either way will work for me, just want to know which way to go and how to install and activate it.

Also, what exactly does this do? Does this mean that when the large image from the 'item' page pops up that it will be able to scroll through a few other images or will it show a gallery style large image with smaller thumbnail images under it?

Note: It says there's a AllVideos plugin as well.

You have to get those plugins from Joomlaworks. Gallery Pro allows you to have image gallery at the bottom of a K2 article. Basically you upload zip file with all images and it does the rest for you. You can set in plugin settings how you want your images to display (lightbox and etc.)

Video plugin lets you embed videos into K2 articles. When enabled you can use specify tags for different videos and use them in an article or you can copy&paste embed code into the video tab.

Hope that helps