Mobile banking services are helping on-the-go consumers become smarter about their money, no matter how little they have. The approaches vary but short-term-goal services all advise consumers on what they can afford to spend or save given their varied goals — piano lessons, car repair, haircut, emergency savings — at a time when the middle-class family continues to struggle.

"A lot of people are attacking incremental elements of an enormous question: Is there a better way to help people manage their money on digital devices?" said Mark Schwanhausser, director of omnichannel financial services at Javelin Strategy & Research.

Some are aiming to coach users to build a savings habit by gamifying and/or automating the task of putting away small amounts (Digit, Qapital, Acorns, USAA's newest app), while other services are spitting out estimates on how much consumers can afford to spend on any day given their goals and upcoming bills (Simple, Level Money, PNC).

"People want more control over their finances," said Scott MacGregor, a user experience consultant. "They do mental gymnastics."

All have a shared pursuit to make consumers feel more in control of their money — an increasingly important feat as ever-more people work on demand and earn volatile incomes. And some have learned from a mistake made by early personal financial management providers: requiring too much effort on the user's part.

The new crop of apps tries to reduce money anxiety without overwhelming consumers with ledger-like visuals and tedious to-dos.

Rather, the cutting-edge services include slick user interfaces that automate tasks, showcase the most pressing financial data bits with calls to action and congratulate users on their progress — attempts to spark engagement on a subject Americans likely feel apathy or pain about: banking.

The tradeoff in using some of these services, however, can mean earning less interest in addition to demanding multiple logins from consumers. The experiences, after all, demand app hopping of consumers wishing to improve their money habits. And what they can't do, of course, is magically make money appear for people who are struggling to decide what bill not to pay.

But a growing number of firms, including banks, believe there is an audience in need of digital services to help them purge the overdrafts in their lives as they work to build wealth at whatever pace works for them.

"Small changes add up to big results," said Neff Hudson, assistant vice president for emerging channels at USAA, an institution that announced a savings app in late July.

And the smartphone, always close to the owner's body, is seen by fintech enthusiasts as a device that offers the perfect opportunity to reimagine the way people interact with their money. Below are the best apps designed to nudge people away from their spend-happy selves without coming across like nagging relatives.

Savings Builders

Americans have little savings to pay for unexpected expenses. According to data compiled by Moody's Analytics, adults aged 35 and under had a savings rate of negative 2% in 2014. So a handful of services are working to improve those stats by training consumers to move small amounts of money into their savings accounts. Think of them as digital equivalents of finding pennies under the cushion.

Digit communicates with users via text rather than a mobile app. It sets itself apart in the way its technology automatically transfers varying amounts of money from checking to savings every few days, based on what its algorithms believe someone can afford. The experience is meant to be playful, so expect tongue-and-cheek messages like gifs of Bill Murray. Users, however, will not earn interest on the accounts yet.

Qapital lets users customize the triggers that automate savings transfers. They can set rules so money is moved into a savings account — currently held at Lincoln Savings Bank — after they buy a latte or pen a Facebook update status, for example. The app also lets people insert images of what they're saving up for such as a flight to Montana, a feature that speaks to the startup's larger goal: become the Pinterest of financial services apps to motivate people to save.

Acorns automates investments of spare change in exchange-traded funds, so the user doesn't have to think about siphoning off their savings, or choose not to on second thought. Every time a consumer buys something via a credit or debit card, the algorithm rounds up to the next dollar and invests the difference. There is a fee for the service unless the user is under 24 years of age or a student.

USAA's Saving Coach app will crunch financial transactions to suggest what it thinks the member can afford to put away on a daily basis. It also layers in atypical features like text and voice command technology and gaming techniques. When a person decides to eat in rather than order pizza, he can inform the app so it will move money he would have spent from checking into savings, for example. The app, which is available to all USAA members who have checking and savings accounts, is targeting millennials.

Spending Insights

Another entry point for personal finance startups is crafting mobile experiences meant to better educate someone about their spending in a quick, simple manner, without destroying their morale.

Level Money, now owned by Capital One, bills itself as a financial GPS so consumers can save themselves from the dreaded b-word: budgeting. The app estimates how much users can afford to spend on any given day and highlights how much they've spent on a category like wine.

In June, the service announced an update further setting it apart from the personal finance app herd: its cash flow models, once tied to 30-day calendars, were adjusted to better accommodate users with irregular work hours, such as coffee house baristas and Uber drivers.

Simple, now owned by BBVA, paved the way for what a modern-day bank account could look like through a mobile phone. The account pioneered a safe-to-spend feature — a short-term cash-flow forecast — along with the promise of no overdraft charges. Other edgy features include letting consumers turn their debit card on and off through the mobile app and acting as a benevolent bandit that takes spending money in small daily increments toward a savings goal if the customer wishes.

PNC Virtual Wallet estimates short-term cash flow so customers can see their money in a more telling way. The service not only shows danger days — when the person might be at risk for overdrawing the spend account — but also comes with playful features like letting someone punch the pig to move money from their checking account into savings. And the Money Bar tool (above) gives them another way to adjust their savings levels.

This is the second in a series of articles about top banking apps. First up was 'What It Takes to Build a Top-Rated Banking App.' Next: 'Top 6 Mobile Banking Apps for Business.'