Healthcare apps on smartphones are becoming more popular each minute – and they’ll continue to grow in the future. At a recent health IT conference, Spring Nextel CEO Dan Hesse said two-thirds of doctors use smartphones, and predicted the number would reach 80 percent in the next two years. Apple leads the pack with about 5,000 apps. The number will explode again, thanks to the iPad. Google’s Android has about 500 health apps. BlackBerry users can choose from about 150.