I bought it. It is really nice if you want to sketch a little graph.

This app is AWESOME. Perfect combination of graph drawing/sketching and actual numerical representation.

I've been looking for something like this, it's a pain to draw basic graphs in other apps. This thing is great.

Very nice concept - I can see this a very useful tool. Lacks bar/pie/etc graphs though - I'd like to see what they have in mind for version 2.