Triangular Scales app for iPhone and iPad

Triangular Scales brings the draftsmans "triangular scale" tool to your iPhone and iPod Touch.

HOW TO USE
+ Flip the scale by either flicking the screen or shaking the device.
+ Drag the scale to move it around the screen. Push the scale all the way to the left, and you can actually use your device itself to make measurements.
+ Select the unit of measurement, with meters and inches available.
+ Adjust the print size (scale) setting, and get ruler lines that match a specific paper size. (Pro Version only)
　* All ruler lines displayed are designed to be as accurate as possible.