Sorry to say that here. I would have preferred by email, but I haven't found any contact informations, neither in the application, nor on the website.
Well, the application icon is part of my pack "Blend". They are released under Creative Commons 3.0 ( http://creativecommons.org/licenses/by-nc-sa/3.0/ ). This is a fair license I think, that means you are free to use it in any non-commercial project without asking me first (so that's fine), as long as you attribute the work to the author, and I don't see any credits.