Since we have started to develop mobile applications (on J2ME platform), we have collected many references with business applications based on high performance, responsibility and robustness. The most complex mobile application created by CodeVision Ltd. was developed last year for Hungarian Telekom Inc., which supports comprehensive business processes. An elastic, JSON-based communication library creates the opportunity to interpret Java Beans at client side, on IOS, Android and WinMobile platforms. In this application client-side persistent caches, optimized network communication and modern user interface components help to improve user experience.