This app will do several things for you.
First, by selecting a Start Weight and a Bar Weight, it will tell you how many plates of each weight you need to add to each side of the bar to get the desired weight.
It will also let you know if you have enough weight plate combinations to equal the desired weight based on the number of weight plates specified on the first screen.
If you select an End Weight, it will show you this information for the weights between, and including, the Start Weight and End Weight.
Useful for any type of weight lifting, power lifting or body building.