Is there a program that draws my signature with the mouse?

So many website wants me to draw my signature with the mouse, and it's horrible. So I want a program that moves the mouse cursor and traces my signature. The program would: 1. Ingest a JPEG of my signature. 2. Create a hot-key that, when pressed, 3. Has me rubber-band the rectangle for the signature area, then... 4. Move the mouse to follow the ingested signature with the mouse button down, making programs like DocuSign think that I'm actually singing my signature. Is there anything like that for the Mac or iPhone?