The overall purpose of this project is to develop a cross-platform CPR (cardiopulmonary resuscitation) application mainly for iOS and Android devices. This application aims to guide healthcare workers in the different processes and expected medication during cardiac arrest, which can often be a fast-paced and stressful scenario. The application will need to provide time-based and previous action-based recommendations for following medication and steps. Each step taken as well as at what time it was performed will also need to be documented automatically through the usage of the application.  This application is implemented using the framework React Native. Facebook developed React Native in 2015 targeting mobile application development. The base structure of React Native is based on React, a JavaScript library released in 2013 used to build web interfaces. React Native allows creation of mobile applications that can run on iOS and Android devices with a single codebase.  This project resulted in a mobile application capable of running on both iOS and Android platforms. The application has enough functionality to be used in a simulation for the CPR procedure during a cardiac arrest rescue scenario. / Det övergripande syftet med detta projekt är att utveckla en cross-platform HLR (hjärt- och lungräddnings) applikation främst för iOS och Android enheter. Syftet med denna applikation är att hänvisa sjukvårdspersonal genom de olika processer och den förväntade medicineringen vid hjärtstopp, vilket ofta kan vara ett väldigt hög tempo och stressfyllt scenario. Applikationen kommer behöva ge tidsbaserade och tidigare åtgärds baserade rekommendationer för följande medicinering och steg. Varje steg  som tas samt när de tas kommer även behöva dokumenteras automatiskt genom användandet av applikationen.  Denna applikation implementeras med hjälp av ramverket React Native. Facebook utvecklade React Native 2015 med inriktning på mobilapplikationsutveckling. Bas strukturen hos React Native är baserad på React, ett JavaScript bibliotek släppt 2013 som används till att bygga webbgränssnitt. React Native tillåter skapande av mobilapplikationer som kan användas på iOS och Android enheter med en enda kodbas.  Detta projekt resulterade i en mobilapplikation kapabel att köras på både iOS och Android plattformar. Denna applikation har tillräcklig funktionalitet att användas i en simulering för HLR proceduren under ett hjärtstopps scenario.

During the last ten years the market for smartphones has grown drastically. Because of the current state of the market with different operating systems many smartphone applications need to be developed for several platforms. With this thesis, the goal was ultimately to contribute to the understanding of cross-platform development as a way of developing smartphone applications. React Native has been evaluated as a framework with which development is done for both Android and iOS using the same code. To study React Native as a framework, a smartphone application for Android and iOS was developed at an Uppsala based IT-company with expertise in web services, smartphone applications, and online gaming. Furthermore, performance tests and user tests were conducted in which React Native was compared to native applications and applications developed using Xamarin (similar cross-platform development framework owned by Microsoft). It was evident that using the same code for both Android and iOS was time saving. However, the performance tests results showed that applications developed with React Native did not perform as well as the native and Xamarin versions. Leading to the conclusion that choice of framework when developing cross-platform applications need to take into consideration performance, development time, and programming language preference.

Today, there are a handful of different platforms for mobile phones. Writing an application natively for each mobile operating system is time consuming and expensive. This situation has created a need for using cross-platform frameworks, that allow programmers to create an application once and run it on all platforms. The problem is that it is not certain whether cross-platform apps can fully replace native ones, or if by using cross-platform tools some desired qualities are lost. Investigating this issue would allow to find out which one of these two application development methods is better, or in which situation it is better to choose one over the other. Such knowledge would allow to decrease development time and costs. Companies that create mobile applications on a daily basis have expertise in this area. Thus, thirteen interviews were done with thirteen distinct businesses in order to research this problem. The results showed that native development produces higher quality applications, but there are some situations where it might be better to use cross-platform frameworks.