The Ad-Changer Plugin for WordPress supports showing responsive banners on multiple WordPress sites. You can suggest variations per each banner which will show only for specific devices based on their screen width.
CM Ad Changer supports both Video Ads and HTML-based Ads. Both Ad types are used as banner Ads, and contain a weight parameter which defines the total appearance percentage in comparison with other Ads in the same campaign.
Video Ads can either be served from a local host or a cloud storage, including video networks such as Youtube and Vimeo. Textual Ads can be linked like any other banner Ad to a target location of your choice.
Campaign Groups is a way to manage several campaigns on the same Ad Spot. Campaign groups are comprised of several campaigns, each including its own weight within the group. The campaign group is defined by placing a shortcode in your template, widget or any other place within a page or a post. Once the page is rendered, the Ad-Changer client connects with the Ad-Changer server, who randomly serves a chosen campaign out of the campaign group based on its weight.
More info and free downloads are available on https://adchanger.cminds.com