Questions still surround whether mobile banking will drive member growth and if it will increase wallet share to current members, given that the technology is still in an early stage.

However, there are strong believers that mobile banking puts credit unions in the game with their younger members.

"We are reaching out to that age group with our mobile apps," said Sundie Seefried, president/CEO of the $221 million Partner Colorado Credit Union in Arvada, Colo.

Some also believe few credit unions can compete toe to toe with big banks in building out branch networks and that branches may be considered analog in a world that is increasingly digital. 

Javelin, the San Francisco-based research firm, charted the fast forward growth in mobile banking in a February report. Mobile banking adoption surged by 63% in 2011, rising to 57 million from 35 million U.S. adults, an increase of 22 million consumers in just one year. Over the next five years, mobile banking is projected to increase at a steady compound annual growth rate of 10.3% as financial institutions roll out new offerings and the pent-up backlog of demand is eased, according to Javelin.

Some credit unions want to ride that wave and, right now, there is a rush to put out mobile banking offerings across multiple platforms such as smartphones with iPhone and Android being the typical first choices. BlackBerry and Windows Mobile apps are trailing others, experts have said. Increasingly, tablet computers, notably the iPad, are starting to get purpose-built apps.

"There now is just so much interest in tablet banking," said Geoff Knapp, a vice president for digital channels at Fiserv.

The question remains on whether this activity will translate into dollars. Early reports are upbeat and at least one credit union is reporting positive results.

Teresa Halleck, president/CEO of the $5.4 billion San Diego County Credit Union, underlined what she sees as the competitive necessity of mobile.

"To be competitive you must offer the same mobile services as the big banks. [Our] members appreciate the ability to bank on the go, and especially like our convenient mobile deposit service."

Halleck said SDCCU continues to see a steady increase in new accounts and the number of active mobile banking users correlates. Usage of its mobile deposit program increased 75% over the previous month and mobile banking has increased total active users by nearly 350% since this time last year.

The $598 million Michigan First Credit Union in Lathrup Village, Mich., is also seeing its mobile banking program grow, said Darlene Fisk, vice president of electronic services. Users and transactions grew from 3,310 to 14,233 transactions in February 2011 to 8,311 and 39,795, resepctively, in February. Downloadable application usage has nearly tripled in the same time frame.

Mobile banking has doubled in the past two years at the $3 billion Mountain America Credit Union in West Jordan, Utah, said Tony Rasmussen, senior vice president. Nearly 10% of members are regular users, and they are seven years younger than members who do not use mobile. The average user's age is 32 and they use 33% more of the CU's services. Retail loan balances of mobile banking users are 13% higher than nonusers, and deposit balances are 15% lower.