EDIT 3 (January 2016)
I’ve taken up support for this plugin again :).
I’ll update the main post when new versions are available.
EDIT 2 (August 2015):
Unfortunately Chartboost has informed me that they will not be taking over the plugin as mentioned earlier. They will revise their decision again later this fall, but this means that the plugin is now unsupported and no updates will be made.
I’ve contacted Chartboost and they said they *might* be willing to take over the plugin although they have no Corona Enterprise developers at the moment and we can’t assume they will take over the responsibility to maintain it. CoronaLabs have told me that the plugin will remain available on their server for anybody to use, however it will not be updated.
The plugin is already Open Source on GitHub under the MIT licence, which means existing Enterprise developers may do whatever they like with it. Anybody is welcome to fork the project and maintain a local copy or just use it as a template for plugin development with Corona Enterprise.