StairBuilderPro is a unique stair stringer layout tool designed specifically for the iPad.  Simply enter your dimensions on the graphical interface and StairBuilderPro will plot all of your points on your stringer. Then connect the dots and cut along these lines.  No need for a framing square and no need to have previous knowledge for building stairs.  The only tools you will need are a pencil, tape measure, straight edge and a saw!