15-year-old Antonio Ferris wants to help people avoid credit card debt. What better way than with an app?

At 15 years old, Antonio Ferris is too young to own a credit card. But he knows more about them than most adults.

The teen from Mesa, Arizona, wrote an Android app called the Cost of Credit Calculator that went live on the Google Play store last month. It shows how much you pay the credit card companies when you only make minimum payments, and how much paying a little bit more can save you hundreds of dollars.

It’s not the only credit card calculator — in fact, a search of the store turned up 250 other apps — but Ferris said he created his because “there weren’t any free ones that did what my app does.”

“I’m sure there are other apps out there that cost money,” he says, “but it’d be hypocritical to charge people for a way to make sure they’re getting out of debt.”

While he’s not charging customers to use the app, creating it wasn’t free. Ferris built a PC version last year after taking a summer programming course. Then he spent more than $200 to hire a programmer to write an Android version.

He asked his father, Bob Ferris, to help out — but not with the bill. He asked his dad to help test the app for bugs. The $200 for the programmer came from Antonio’s unspent birthday cash and his earnings as a babysitter for children in his church.

“The most proud moment for me was when Antonio, who wouldn’t spend money on himself for years, was willing to spend hundreds of dollars of his own money to pay the programmer so the app could help people he doesn’t even know,” Bob Ferris says of his son.

How much difference $10 makes

Antonio isn’t a big spender. The last thing he bought for himself was a movie ticket to see Guardians of the Galaxy last August.

“I am a really big saver,” he says, laughing. “I really don’t spend that much money.”

He’s also a whiz with numbers — for fun, he creates math problems for his parents to solve — and as a sophomore in high school, he’s taking calculus for college credit because he wants to become an electrical engineer. So he was flabbergasted when his grandfather told him about a close friend who pays the minimum on his credit card each month.

“The minimum payment is usually very little over the interest,” Ferris says. “75 percent of what you pay minimum will a lot of times just go to the credit card company, and only one-fourth of it will go to interest” and principal.

If that’s all you’re paying, you’re barely treading water. And the longer you take to pay off the debt, the more money it costs. But a lot of people don’t think about that.

“It’s very complicated and hard to understand the ins and outs. It’s hard to know everything,” Antonio says. So to make it easier to understand, he developed his app, which shows how much money you can save by paying just $10 more a month — basically the cost of a movie ticket.

How his credit calculator works

Let’s say you’re planning to buy a new iPad Air 2 for $500. You don’t have that in cash, so you want to put it on your credit card. When you open Antonio’s app while you’re standing in the checkout line.


You type in $500 where it says “item cost”. You tap the minimum payment button, and then the “find true cost” button. The app does the math and tells you…

You’re going to be out $698, and it’ll take almost four years to pay off.

That’s a waste of $200 and a long time to worry about a tablet that’s going to be obsolete soon. You hit the “Pay $10 more” button.

The calculator says: $631 in 32 months. Hit it again: $580 in 20 months.

That’s better. You leave the store knowing that paying an extra $20 per month will save you $100 on your new iPad in the long run. (That may not sound like a lot of savings, but chances are, iPads aren’t the only item you put on your credit card.)

But where did that minimum payment come from? The app has a settings page where you can change the interest rate (default is 18 percent) and minimum payment (default is 2 percent of the purchase) to fit your credit card’s rates.

A proud father

Here’s the oldest five-star review on the app’s download page: “Useful. Simple and useful app. Great way to know how much you’ll pay if you pay minimum amount.”

It was written by someone very familiar with how the app works: Antonio’s dad. He just wishes it had been available sooner.

Around when Antonio was born, Bob Ferris remembers he and his wife had a combined credit card debt of nearly $100,000, mostly from the costs of college and starting a business.

“We were able to pay it off over the course of several years, but I think if Antonio’s app was available at that time, we would have paid it off sooner and saved significant money in the process,” Bob says.

Now Antonio is learning how to port the app for Apple users. He hopes to launch it in iTunes store this summer.

Then as a reward, maybe he’ll treat himself to another movie.

free debt analysis call 855-654-9191

Meet the Author

Jess Miller

Jess Miller


Miller is the former assistant editor of Debt.com.

Budgeting & Saving, Tech

apps, credit card debt, credit cards, eliminate debt

Related Posts

Article last modified on October 9, 2017 Published by Debt.com, LLC . Mobile users may also access the AMP Version: Meet The Teen Whiz Who Invented A Free Credit Calculator - AMP.