Instaviz does the same thing, but yours is free, and your execution is better, great job...
<sarcasm>Cue to patetent lawyers in 3...2...</sarcasm>
<sarcasm>Cue to patetent lawyers in 3...2...</sarcasm>
And regarding the instaviz, this very restrictive. It does not allow you to rearrange the shape the way you want.
The sketch recognition might be patented (at a minimum there is previous art), and I know it is only one piece. But that is enough to create some unwelcome letters. And it is also the reason why I am against patents. This is a case where copyright is enough, and IP would be counter-productive
Kudos to you for figuring out shape recognition. It took me a long while to get my head around it.