Budgeting doesn't have to be unpleasant, and mobile apps that track spending don't have to offer snarky feedback.

That's the concept, ultimately, behind JPMorgan Chase & Co.'s (JPM - Get Report) Finn, a mobile-only checking and savings app. the largest U.S. lender is rolling out this month in St. Louis and eventually to the rest of the country. It lets users track their spending and savings based on their own goals and preferences -- and their emotions.

The app learns how users feel about their purchases through a tap-and-swipe emoji tool that may give Tinder users a feeling of déjà vu. It also shows them how a debit jibes with the spending plans they programmed into the app previously and enables automatic transfers from checking -- where payroll checks are often deposited directly -- to savings, based on the amount and whether it made the user happy or sad.

"We were seeing a growing trend and data out there that pointed to millennials feeling stressed about their finances and not necessarily feeling like their banks understood them," Melissa Feldsher, head of Finn, said in an interview with TheStreet. "And so, we went out there to go and talk to millennials and understood what their needs were. We found that there was a need for a differentiated experience for them."

Relying on the results of those interviews, conducted around the country over a period of more than a year, Finn was developed by the bank's digital team, which works out of a Google-esque office in midtown Manhattan replete with sofas, conversational spaces for brainstorming, games like Foosball and snacks.

"When it comes to money, millennials told us they don't want to feel like they're being judged," Bill Wallace, CEO of Digital at Chase, said in a statement. "So, we designed Finn to put them in charge, no matter where or how they're spending."

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