Every once in a while you need to draw a graph to quickly convey some information, and you don't want all the hassle of opening paint, drawing whatever you want, exporting it as png, and all that stuff. Sometimes it's just easier to do it as ASCII art, only you don't want to spend hours carefully aligning pipes and dashes. For these times Asciiflow exists.
Give it a try, it's a great way to quickly generate a diagram. Just remember to use monospace fonts.