This is a simple Joomla plugin for substituting some code to produce a button wherever requested.
I simply zipped the directory up, then installed it like any other Joomla extension would install.
Very simple syntax. It knows how to produce two types of buttons, chosen by the syntax you use to activate it:
{pkapply}
or
{osapply}
The code it inserts depends upon what you have configured the plugin code to use (got to Extension Manager -> Plugins and edit the plugin to see the text boxes.
It knows about one variable at the moment, the title of the article it is embedded in. You call for it to be processed and inserted by including "{title}" in the code to be inserted.