Among the smartphone users in America - 77 percent of all U.S. cellphone owners - 53 percent said they'd used mobile banking services or applications during the past 12 months, according to a Federal Reserve study.

But what about the other 47 percent? Some undoubtedly belong to the group that the Federal Deposit Insurance Corporation considers underbanked - using only the most basic bank services - which constitutes nearly 20 percent of American households. And then there's the 7 percent of U.S. households whose residents are "unbanked" and don't patronize banks or credit unions.

The underbanked and unbanked frequently choose to manage finances as they do because of distrust for financial institutions or in fear of past debts. Given the size of this demographic, banks and lenders that help these individuals help themselves won't just be practicing common decency, but also exercising good business sense. And mobile services could be just the way to bring the underbanked in from the cold.

Smartphone access is majority access
The FDIC assessment found about 75 percent of the underbanked and 40 percent of the unbanked owned or could access a smartphone. Contractless, pay-as-you-go carriers like Metro PCS and financing agreements have removed the devices' one-time exclusivity to the upper middle class and above. As such, the banking regulator concluded smartphones would be an ideal medium by which to extend economic inclusion to lower-income Americans. 

Because the survey also found that numerous underbanked Americans prefer to visit bank tellers for their needs, it's important not to force mobile banking and finance apps on these individuals. Promotional measures should stress these solutions as an augmentation of traditional banking, not a replacement.

Financial apps widely available
Countless general-use finance apps are available on smartphone app marketplaces, in addition to those from specific institutions. For example, PC Magazine highlighted Mint's usefulness: It manages multiple banking and credit accounts, while also providing credit scoring and investment analysis. LearnVest serves similar purposes but provides direct access to a financial advisor for premium members. 

Role of alternative credit
Lenders who have reservations about the financial viability of low-income underbanked Americans should consider assessing them using an alternative credit report, with credit decisioning tools from Microbilt. This allows potential customers to prove their earnings through utility and rent payment records, along with other documents not seen by credit reports, allowing lenders a better perspective.