One way is to ensure that mobile applications from the companies of iPhone app development in Los Angeles and Android app development in Los Angeles show optimum performance on a given device is to develop the application (app) natively on that device. This means that at a very low level, the code is written specifically for the processor in a particular device. When an app needs to run on multiple operating systems, however, there is little — if any — code that can be reused from the initial development. The application must essentially be rewritten for each specific device.