Many important data sets in modern biological science comprise hundreds, thousands or more individual results. These massive data sets require computational tools to navigate results and effectively interact with the content. Mobile device apps are an increasingly important tool in the everyday lives of scientists and non-scientists alike. These software present individuals with compact and efficient tools to interact with complex data while at meetings or otherwise remote from their main computing environment. We believe apps will be important tools for biologists, geneticists and physicians to review content while participating in biomedical research or practicing medicine. We have developed prototype apps for displaying genomic data, using the iOS platform. To understand the software engineering requirements we review the model-view-controller scheme for Apple's iOS. We apply this scheme to a simple app for gene expression query tools, and we made this tool is useful in the case of locally developed microarray data. The challenge of this application is to balance between local content stored within the app itself vs. remote content obtained via a network connection.