The present invention is a system and method for creating, developing and testing cross-platform software for mobile communications devices. The invention enables mobile device software that must be highly-integrated with the operating system on which it runs to be implemented in a cross-platform manner. Security software for mobile devices is a prime beneficiary of the present invention, as a substantial proportion of its functionality is identical between different platforms yet integrated very specifically into each platform it supports. The cross-platform system includes a core platform-independent component, a platform-specific component, and an abstraction layer component, each of which may communicate with each other using a common defined API. The present invention enables the platform-independent component to be completely re-used between platforms and allows the platform-specific and abstraction components to contain minimal amounts of code on each platform.