In the current version it will throw an error since it’s pulling the twitter js (and others) from an insecure URL. In dd-class.php you will need to change the two references from…
https://platform.twitter.com/widgets.js
to this to pull the https when needed…
//platform.twitter.com/widgets.js
Note that there are other references to https://
so you will need to change it to //
anytime the code is pulling file (like a js, css, image file, etc).
The downside is that until this becomes implemented into the core code of the plugin, anytime you install an upgrade of this plugin you will have to go back in and manually change these references.