A straightforward but powerful application to validate ballistic values. Given the Muzzle Velocity, Ballistic Coefficient, Zero Range, Sight Height and Target Range, the PoI (at the target Range) is calculated. If this PoI value is measured to be incorrect then, on entering a new PoI value, a list of possible corrections is displayed any of which can achieve the measured PoI.
This sounds a lot more complicated than it actually is!