Is there official material and public API for developing Kibana plugins that is not this series of articles (https://www.timroes.de/2015/12/02/writing-kibana-4-plugins-basics/)? Thanks.
Nothing formal right now, unfortunately, but we're working on it.
One resource we do have is the yeoman generator for Kibana plugins.
You may also be interested in a webinar happening next week: The Contributor's Guide to the Kibana Galaxy
It's also worth noting that everything you know as Kibana (visualizations, discover, dashboards, elasticsearch communication, etc) are already built as plugins. Anything in the src/plugins path is a standalone plugin, as would be installed vis the command line tool.
As the REAME notes, the plugin system is still a bit in flux. Things are still changing as we continue to build our own plugins. I don't mean to discourage you, just to make you aware. There's not huge, sweeping changes in the works, but some things may break along the way as we work towards future releases.
Thanks Joe,
I used the yeoman generator to create a plugin but the stub it generates does not work with kibana 5.0.0-snapshot. I modified the plugin looking at another one (sense) and I was finally able to see the simple html. However, I'm still not able to see angular expression {{}} resolved. I created another post with the details of what I did just few minutes ago. Any help would be appreciated.