The Thunderbird addon provides the necessary codebase support for creating toolbar buttons.
The add-on's versatility is not limited to users only, as extension developers can also take advantage of its benefits during the development cycle. By prototyping JavaScript code within a custom button, developers can avoid having to constantly reload chrome until the code is proven to work. Later on, the code can then be moved over to the add-on.
Using Custom Buttons 2 for Thunderbird can also make it easy to convert bookmarklets into buttons, allowing users to perform their favourite tasks with just a click of a button. In conclusion, the Custom Buttons 2 for Thunderbird add-on offers a lot of functionality and ease of use, making it a must-have tool for both users and developers alike.
Version 3.1.0: N/A