When the iPhone launched in 2007, followed by the first commercial Android device in 2008, nobody knew how big the market for mobile apps would grow. Roughly a decade later, it’s clear that apps have changed how we live and work. The iOS App Store and Google Play have more than 2 million and 3.5 million apps available, respectively, according to new data from research firm App Annie; more than 40 countries will generate $100 million in revenue (each!) from apps. App Annie predicts that app stores will gross $100 billion worldwide in 2018, which translates into a year-over-year growth rate of 30 percent. That’s a stunning figure, but it’s not totally great news for individual app developers. Although App Annie argues in its report accompanying the data that recent adjustments to the layout of the iOS App Store and Google Play will make it easier to “showcase newer and lesser-known apps from independent publishers,” resulting in revenue gains spread “across a broader group of publishers,” anyone who builds apps knows that discovery remains a huge problem. To put it simply, it’s hard to make a buck as an app-builder when your potential customers have millions of options out there. Compounding the difficulty is the sad fact that a successful app is copied in relatively short order. It’s worth revisiting the case of Dong Nguyen, creator of the ultra-popular “Flappy Bird” game in 2013; although he reportedly earned as much as $50,000 a day from in-app advertising and purchases when the game became a smash hit, app stores were soon flooded with dozens of (often poorly-made) clones. And as an app developer, even if you avoid wholesale copying by smaller developers, large firms may update their own products to mimic your best features. Add to that the relatively limited “shelf life” of apps (which, depending on the researcher, can range anywhere from six months to 17 weeks), and it’s clearly hard out there to make a sustainable buck in mobile development. All that being said, the sheer size of the ecosystem means lots of opportunity for those with the right skills, whether they work for a large or small developer. The need for those who can create great iOS and Android products clearly won’t slacken anytime soon.