How to make an app: what dev tools do professional app makers use? What do you need (or need to know) to make apps? We looks at the toolsets and assistance available for developers of smartphone apps. Smartphone makers may be rushing out upgrades to their mobile operating systems as quickly as they can write them, but developers face different challenges, both in keeping up with the changes, and maintaining the appropriate tools necessary to keep them up to speed. And while each smartphone vendor offers its own toolsets and assistance for developers, comparisons show there are still major differences between the quality and effectiveness of the developer tools currently available. This fact quickly became evident to Rich Larcombe, a web and mobile application developer with Melbourne-based PepperStack. A longtime user of Microsoft's popular Visual Studio.NET integrated development environment (IDE), Larcombe has become intimately acquainted with the variations between smartphones. He has progressively worked on Android, iPhone and, most recently, BlackBerry versions of the company's flagship NeatStreets application. PepperStack's Rich Larcombe. Designed to let citizens note and report local issues of concern ?? for example, damaged footpaths, graffiti or vandalism ?? NeatStreets has highlighted many differences between the platforms' development tools. Android's software development kit (SDK) is effective enough, he says, but has an extremely slow smartphone software emulator on which developers can test their apps during development. Apple's iOS SDK is far more feature-rich, with a robust iPhone emulator and rich tools for building apps' graphical user interfaces (GUIs).