This was not a typical data entry screen, as it actually requested the load in pounds. Most of the entry keypads don't show the proper units or any units at all. I found it annoying to have to use this calculator to enter numbers when I should have been able to do it just with the regular iPhone number keypad.
Nowhere here are units of length, modulus OF elasticity or moment OF intertia shown. You could mix or match units to your heart's content and come up with a totally worthless answer, and this app wouldn't warn you.
This calculator actually asked for the load in pounds and the thickness of the plate in inches, one of the rare cases where I felt they actually did a good job. Still, they should cite the sources for the formulas.