For several decades, market fragmentation caused by different operating systems has been complicating and overpricing the process of creating new applications. Unified development for multiple platforms does not only save time and expenses, but also enables to reach a far wider audience. This work presents the topic of a cross-platform mobile development and analyzes the development of the market for currently the two most prevalent operating systems – Android and iOS. The results of the analysis are used to design and create a multiplatform tool intended to monitor immunopathologic reactions. The work also includes a marketing plan and expected economic valuation once the developed application is introduced to the market.