When Alex Kinnier and Wayne Lin left Opower at the end of 2015, they took some of the cloud-based software company’s values with them. They appreciated how Opower was working to save money on basic necessities—utilities—and wanted to provide the same kind of service to consumers. So they looked at transportation costs, which people usually can’t avoid, and set their sights on a new app-based rewards system to save money at gas pumps.

“When we left Opower and started thinking about our next venture, we really focused on doing something to help people and give them more of an edge,” Kinnier told DC Inno. “We sat back and thought ‘What are all of the things that people need?’ This isn’t like going to a high-end spa. It’s things that people need every day.”

The new app, Upside, plays on a simple premise. People want to save money buying gas and gas stations want to see more repeat customers—especially when Kinnier says that 75 percent of gas station customers don’t come back. And it’s only available in D.C. and Baltimore right now.

Upside (not to be confused with recently launched Upside Travel) is free to download. Gas stations can join for free as long as they offer to give Upside users a free deal as a way to encourage repeat customers. And the startup limits it so that only one gas station per block can sign up for Upside. To use the app, users download it, assess the map of possible deals, and then once they get their gas, they upload a picture of their receipt to get cashback through PayPal or a check in the mail.

Alex Kinnier, Upside

“There are inconvenient ways to beat the system. You can drive to Costco and have a membership there and get cheap gas there,” Kinnier said. “What we’re trying to do is make it so that the necessities of life are easier to get than what you get today and pay less for them. We get a lot of happiness out of that because it makes a difference for people.”

Upside makes its money on a “pay-for-performance” basis. There’s no upfront payment from the gas stations that work with them, but when the stations get repeat customers, Upside takes a small cut of that profit. To date, users have saved about $45,000 on the app in the six months since it has launched. Per pump, users save about $1-$2, Kinnier says. The two founders also say that they’re getting a lot of interest from Uber and Lyft drivers and commuters in the DMV.

Users aren’t the only ones bringing in cash. Gas station owners have seen $244,000 more in sales than they would’ve before.

“The merchants are winning because they’re getting these customers that they wouldn’t have gotten otherwise,” Kinnier said. “This only works if both sides are winning.”

As of Friday, the app has about 12,000 users, and they didn’t start pushing the app until a month ago.

Wayne Lin, Upside

“A lot of our marketing comes from our users,” Lin told DC Inno. “‘It’s a free app that gives you free money,’ that came from our users. They kept writing that over and over again.”

Eventually, that would be worked into the startup’s tagline, which is now “Free app for cash back on gas.”

In the future, Kinnier and Lin hope to see the app expand past gas pump savings and into another industry like groceries. They also have their eyes set on Philadelphia and the rest of the Northeast for expansion.

“Our goal is to help people save on things that they buy every day,” Kinnier said. “We just started on gas because it’s something that people buy routinely.”

Image courtesy of Upside.