Generate app icon files from a highres source. Put in your bash aliases then call generate_app_icons source.png

aliases

function generate_app_icons {
	icons=(29 40 50 57 58 72 76 80 87 100 120 114 120 144 152 180)
	
	for i in "${icons[@]}"
	do
		resize_image $1 $i
	done
}

function resize_image {
	cp $1 Icon-$2.png
	sips -Z $2 Icon-$2.png
}