The boys say development took them a while and they're pretty satisfied with the outcome.
"I wanted it to be able to help people practice facts. I didn't really have super high hopes for it. I just wanted to make it work and get it out there," said Owen Voorhees, MathTime creator.
"I was happy that um. it would be out there and people could buy it," said Finn Voorhees MathTime creator.
The app costs 99- cents to download. Once sales reach $250, 70 percent of each sale will go to the kids.
Both boys tell us they're thinking about careers in computers.