Ruler Plus
Offers an extended ruler.
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Scale Ruler
This ruler is specifically for those building model railroads. It contains a ruler, an automobile, a human angle chart and rail height reference for G, O, S, HO, N & Z scales.
Protractor
Photo-based virtual protractor. Measure the angle of anything that can be captured with your iPhone’s camera.
Protractor 1st: Pro Angle Finder
Handy in the classroom. Measure angles in three different units: degree, radian, gradian and revolution.
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