From CNC Consulting:
The Machinist Calculator has been developed to quickly solve common machine shop trigonometry and math problems at a price every machinist can afford!
As a machinist or CNC programmer, you often have to use trigonometry to calculate hole positions, chamfers, sine bar stacks, dovetail measurements, bolt circles, etc. You often have to leaf through reference books, drill charts, speed and feed tables, thread wire charts and so on to find the information you need. On the other hand, you can use the Machinist Calculator fast, easy and accurate and affordable.
Apps for Android, Apple iOS and BlackBerry also available.