While most bank mobile apps are focused initially on iPhones, then move to Blackberry and Android in subsequent rollouts, it would appear that Android and iPhone are the way to go as BlackBerry falls behind its two rivals in sales.

Gartner says about 417 million mobile phones were sold globally in the third quarter of 2010, up 35% from third quarter 2009—and smartphones now account for nearly 20% of all mobile sales. 
In terms of types of phones, Apple’s iPhone has jumped ahead of Research in Motion’s Blackberry.

More than 13.5 million iPhones were sold in the third quarter, or about 3.2% of the global market. Nokia still rules the roost, with a 28.2% share. Google’s Android is now the second most popular smartphone (behind Nokia’s Symbian), accounting for 25.5% of smartphone sales, up from only 3.5% a year ago. Even though Blackberry sales have grown to 11.9 million from 8.5 million, its share fell from 20.7% to 14.8%. Apple’s share has also fallen despite quarterly sales nearly doubling in one year.

The ramifications of this innovate-or-die culture for smartphones are apparent in the banking industry. Bank of America and Citigroup, for example, are planning to allow staff to use iPhone and Android instead of BlackBerry for e-mail, a move that JPMorgan Chase and Standard Chartered have already made.

Robert Cozza, a principal research analyst at Gartner, said smartphone providers have entered a period of accelerated platform evolution, stimulated by more regular releases and new device types, and any platform that fails to innovate quickly will loose ground.