Herald is a Kings of War app built using Cordova, released under MIT license.
The cordova docs will help you get that framework installed, and from there you can run:
cordova run browser
to start the app in your local browser for testing. There are still a bunch of missing features (e.g. spell selection) but the skeleton of the app is there. Anyone who contributes will be granted editor access to the repository so that we can make progress. Happy to answer any questions.