This simple plugin allows you to specify additional html that will be included in the following places:
After the <head> tag
Before the </head> tag
After the <body> tag
Before the </body> tag
This is most useful for adding links to javascript and css files. It is possible to do this by editing the templates (globalTemplate, IncludeJS, IncludeCSS) but these changes need to be made after each upgrade.
I use this on my board to add some custom javascript functions and to use some google fonts by adding this just before the </head> tag: