Mobile apps—all the cool kids use ’em. These four app builders can help you get in the game.“There’s an app for that,” the snappy slogan that Apple debuted in 2009 iPhone ads, turned out to be eerily prophetic. Demand for smartphone and tablet-based apps is at an all-time high, spurring developers to build more creative, diversified apps to meet consumer needs and expectations. According to data marketing firm Statista, more than 100 billion apps have been downloaded from Apple’s App Store as of June 2015, and mobile app revenues worldwide are predicted to surpass $76.5 billion in 2017. Shopping apps are among the fastest-growing varieties, according to Statista. And if you’ve been considering creating an app for your store, your timing is perfect. Creating a proprietary app that features and/or sells your products has never been easier, thanks to a