This is an app to calculate the amount of liquid in a tank. It was originally designed for truckers to use to calculate remaining gallons/liters in a semi or tractor truck fuel tank.
I've since updated it to be able to calculate the volume of liquid in any size tank, from a few inches to hundreds of feet, of the basic shapes. Rectangle, rectangle with step cut in, rectangle with d-curve on side, horizontal cylinder, or vertical cylinder. It can calculate using US or Metric systems.
Simply enter the dimensions of the tank, the depth of the liquid in the tank, and viola!