Are you asking about a Unity plugin for Flash? Unfortunately Unity support for Flash as been
sunset as of April 23, 2013 so it's unlikely we'll be developing a plugin for Flash. However, we are always listening to feedback posted on this forum so if there's enough interest we can look at the feasibility of creating a plugin. If this is something you're still interested in (or something related like a Unity HTML5 plugin), please let us know and we'll take it into consideration.