How to start creating a plugin


what is the best approach to start creating a web app plugin. My goal i to analyze headers to gather informations about Ciphermail actions and encryption state of incoming mails and display icons to reflect these and perhaps display a popup with detailed informations as I did for Thunderbird:


Hi Matthias,

Good start would be reading documentation and check out existing plugins.


Existing plugins:

This plugin is useful to find the insertion points: