Great plugin, really gonna save some lifes. I have a suggestion that may help increase the icons list.
What about FontAwesome? it's used by a far majority of websites, it's entirely font based (so it's compatible with retina display on the go), I believe is not that hard to make possible to change icon size over 600+ icons and is on OFL license (Open Font License)
This plugin is awesome and can make construct 2 a really beautiful software creator.