When developing mobile applications, the tradition has been to write code specific (native) for each platform they are running on. Usually it’s about writing two separate applications for the biggest platforms, Android and iOS. There exist alternatives to this approach that uses the same code for different platforms. React Native is a relatively new cross-platform development framework that makes it possible to use the same code for application to Android and iOS. It also uses native UI-elements as a possible solution for performance issues that is often associated with cross-plattform development. This thesis evaluates React Native and compares it against native Android. The implementation is done by replicating the main functionality from a social media application written as a native Android application. However, the application is not made as an exact replica since that could limit the solutions in React Native. The evaluation is done in a Startup company and therefore focuses on aspects important in a Startup. Another issue when developing a mobile application is what type of backend that shall be used. Performance, scalability and complexity are all important aspects when choosing a framework or language as a base for the backend architecture.There do exist theoretical frameworks that could be used when building the backend. However, these frameworks require resources that are often missing in a Startup. AWS Lambda is a platform that claims to be a cost-effective way of building a scalable application. In this thesis AWS Lambda is evaluated to see if it can be used to create an automatically scaled backend for this type of social media application. The conclusion of the React Native evaluation is that it can be a suitable alternative to native Android development. If the team has previous experience in web development but lack experience in mobile application development it can be a wise choice since it removes the need to learn two frameworks in native Android and native iOS development. React Native is also good to fast create functional prototypes which can be shown to potential investors. The biggest drawback is performance in animations. However, there are often ways to work around that. In our case this drawback did not affect the user experience of the end application. The evaluation of AWS Lambda concludes that it is not for every project. In this thesis, the application was a bit too database heavy and therefore the autoscaling ability did not work properly. However, for a service that needs a lot of computing power, AWS Lambda could be a good fit. It could also be a suitable alternative if someone in the team has previous experience in the AWS environment.

Today, there are many different ways to handle physical access control. RFID cards and tags are still a major solution but during the last years the market have been focusing on taking advantage of the devices that most people always carry with them, such as smartphones, tablets or smartwatches. This thesis has been carried out together with the company BRP Systems. They develop and deliver business systems to mainly the fitness business. In their product suite there is an application for booking workout sessions at these facilities. In this thesis their booking application has been rebuilt as a prototype and the functionality of unlocking the door and checking into workout sessions has been added. The application has been developed in React Native for Android and has been implemented in three versions using different techniques to sensor the users position at the door. The techniques are iBeacon, GPS and QR code. The iBeacon- and GPS versions work by allowing the user to unlock the door when standing outside it. A local notification will be pushed if the application is in the background. The QR code version allows the user to scan a QR code at the door to unlock it. When the door has been unlocked the users can also check into their booked workout sessions. The system and the different versions have been tested at one of BRP Systems customers to evaluate the usability. The conclusion is that an application with high usability can be built with all tested techniques in React Native. For the system to be used several other factors such as security and maintenance has to be considered. The choice to use React Native might be of high risk since it is a relatively new framework relying on community developed libraries.

The first step of debugging a deployed application is to reproduce the reported bug. But bugs that cause unpredictable behaviors without crashing the applica- tion can be difficult to reproduce, because the developer has to rely on bug-re- ports issued by users. The goal of this thesis has been to develop a diagnostic tool which makes user-reported bugs easier to reproduce. More specifically, the goal has been to develop such a tool for React Native applications implement- ing Redux, taking into consideration both state-data stored in Redux stores and React Native components. Requirements for the diagnostic tool were laid out and partitioned into proto- types that were implemented separately in iterations and then merged into the resulting tool. Requirements were also drawn for three sample applications to test and evaluate the tool, as well as a back-end to prove the tool's capability in uploading and downloading state-data from a server. The thesis resulted in a diagnostic tool that's imported into an already existing code-base as a third-party library, and which collects the complete state of the reported application instance and delivers it to the developer as a single JSON document. The tool can then inject the state-data into a fresh instance of the ap- plication to make it identical to the malfunctioning instance reported by the user; a process referred to as "reviving". Redux stores demonstrated state-over- write protection which complicates state-injection. A study was performed to compare the impact this difference has on performance. As expected, the study revealed that the diagnostic tool takes marginally longer to revive state-data in Redux stores for this reason.

Nowadays almost everyone has a smart phone. In addition, as more people use smart phones more applications are being developed for smart phones. Each operating system on the smart phone market has its own applications. Up until a few years ago, developers had to develop an exclusive application for each operating system in order to cover the whole market. A number of cross-platform frameworks have emerged. These frameworks enable developers to use one code base for every operating system. To be able to use most of the code for all platforms makes it easier to maintain and evolve the application. Two of the frameworks that allow cross-platform development are React Native and Ionic. The purpose and goal of the thesis is to evaluate if Ionic 2 is eligible to use as a cross-platform framework in terms of performance. The method used to achieve the goal is based on replication. An application made in React Native is replicated by using Ionic 2. The applications are then evaluated with focus on performance. The applications are evaluated using AndroidViewClient and Trepn profiler. AndriodViewClient is run outside of the OS of the Android device and can control the GUI of a device. AndroidViewClient is used to automate the tests. The metrics used for evaluating the performance are CPU load, memory usage, battery power usage, the size of the application and the size of the Android package kit. Trepn profiler is an application that is installed on the device. Trepn profiler has access to the hardware of the device and is therefore used to measure the first three mentioned metrics.

The diploma thesis deals with the design, creation and implementation of a software application in the corporate environment of Velká Pecka s.r.o., better known as Rohlík. The first goal is to analyze the given company and find its shortcomings. The second, the main one, is to create and implement a software, which would eliminate them. The resulting solution is a mobile application, which improves issue reporting in their warehouses, thus saving resources overall.

The thesis deals with design and implementation of prototype of mobile application for Android and iOS operating systems. Framework React Native was chosen for realization because it allows multiplatform development. Application focuses on data visualization from sales of handmade products on Fler web portal.

Digitalization is happening all around us as more tasks get software assistance, to ease the workload and improve performance. This opens up for endless possibilities but it also comes with challenges. The progress made within software development means that the first solutions implemented can differ a lot compared to the latest for a company. This spread makes maintenance significantly harder due to having different implementations or even different operating systems. Cross platform compatibility is a technique that battles this spread by allowing for a single implementation to be used in all environments, enabling maintenance to be focused solely on one product. The transitioning towards cross platform applications is easy when there is no  external hardware involved. However when there is external hardware the transitioning needs to take limitations regarding hardware compatibility into consideration, which has been the case for this project. In the thesis, a proof of concept has been developed for migration from native Android towards React Native which allows for a cross platform compatible application. External hardware in the form of a card reader, receipt printer and touch screen are included to analyze the possibility to migrate without having to replace the current hardware due to limitations regarding hardware accessibility and performance. This work shows that it would be possible to transition from a native Android application with external hardware to a React Native application if an additional backend environment is implemented alongside. The backend is for validation and token generation towards third party programs connected to the hardware. This proof of concept shows that the performance loss is within an acceptable boundary which only marginally affects user experience.

Saab is a large swedish company providing a multitude of different products and services. This also means that Saab has to provide support and customer service for said products. Currently this is handled online in Support Portals, where customers and partners can access product information as well as an issue management system called SIRS. In the current situation the system is tailored for a desktop experience, and the workflow is therefore limited in terms of mobility. This project aims to allow the users to be more mobile by investigating the possibility of developing a mobile application for usage with SIRS. During the project a proof of concept of such an application has been developed. The implementation relies largely on using currently available api:s and when necessary porting some code from server to client side. By using various UX-related methods during the development of the application it is expected that the application is user friendly and fits the target audience. When looking at the result of the work, it is indeed possible to integrate a standalone mobile application with SIRS. The application also has usability which is comparable to the current system. However, some limitations were found that required rewriting the existing system to provide necessary data to client side applications like the one developed in this project. To conclude, the application is a proof of concept that shows what can be done without modifying the current system. Some of the major things that has to be modified before taking the application to production, such as stability concerns and testing, is also presented as results of the project.

Denna rapport jämför prestandan hos applikationer utvecklade med två olika verktyg som används för att utveckla mobilapplikationer till flera plattformar samtidigt. Verktygen som jämförs är React Native och Apache Cordova. Verktygen fungerar på olika sätt, React Native renderar applikationen genom att använda plattformsspecifika- komponenter medans Cordova renderar med hjälp av HTML5 och CSS3. Jämförelsen går till genom att utveckla tre applikationer med de båda verktygen (totalt sex applikationer) och sedan jämföra prestandan hos dessa. Testapplikationerna är framtagna för att testa funktionalitet som förekommer ofta hos applikationer idag. Testapplikation 3 testar exempelvis ett oändligt scrollande flöde, som förekommer hos både Facebook och Instagram. Resultaten visar att Cordova i dessa tester har en CPU-användning på 76% lägre än React Native och även har en minnesanvändning som är 18% lägre.

This study compares the performance of two popular cross-platform mobile application development frameworks, Flutter and React Native. As the number of mobile users continues to grow, the ability to target multiple platforms using a single codebase is increasingly important for developers and companies. We conducted three manual UI tests; scrolling through a list, testing the camera, and filtering a large dataset to measure the performance of the frameworks in terms of CPU usage, memory usage, and janky frames on an Android device. The results indicate that Flutter may provide better performance in specific situations when compared to React Native. The study contributes to the existing research by providing additional insights into the performance of these frameworks under specific test scenarios.