When you’re an independent mobile-app developer, you’re often strapped for time and resources. In contrast to the big software-development firms, which can afford to throw hundreds of developers, artists, programmers, and others at a project, it’s often down to you and a handful of employees (if that). In light of that sobering fact, deciding on which platforms to focus your attention can prove a nerve-racking exercise. Do you devote resources to a smaller platform such as Windows Phone, in hopes that the relative paucity of apps will allow your own product to stand out? Should you develop for Apple’s iOS and Google Android, or spend your time producing an ultra-polished version of your app for just one of those platforms? According to a new report from app-analytics firm App Annie (PDF), Google Play saw a spike in downloads in 2015, “driven by first-time device owners in emerging markets.” That spike powered a widening lead in Android downloads over those for iOS, which, in App Annie’s words, “could mark the beginning of major changes in mobile marketing, including substantial increases of Android’s share of mobile ad spend.” Much of that spike came from emerging markets such as Brazil, India, and Mexico. Meanwhile, iOS managed to maintain steady growth in China, the United States, and Japan. Moreover, App Annie saw further opportunities for growth in mobile apps. “Device penetration remains relatively low in a number of emerging markets,” the report added. “Store revenue will continue to grow as audiences broaden and monetization options such as in-app subscriptions gain further traction.” While some developers prefer to develop exclusively for iOS (or port their apps originally developed for Apple’s platform to Android without much QA or polishing), the rising rate of downloads for Google’s platform suggests it could serve as an increasingly attractive target for developers in coming years. On Google Play, games led worldwide downloads in 2015, according to App Annie, followed by tools, communication, photography, entertainment, social, personalization, and music & audio. That was a bit different than the list of top categories for Apple’s iOS.