What does the word "Benjis" refer to?

Benjis is short for Benjamins.  Benjamins is another name for one hundred dollar bills and comes from the portrait of Benjamin Franklin on the front of the United States bill.   Benjis  Benjamins

Why did you choose the name "Save Benjis"? 

It describes what the program should help you do (i.e. save lots of money), it's a cool name (at least we think so), it wasn't taken, and it fits on the iPhone home screen.