The vast supply of different smartphone makes and models, along  with their  accompanying operating  systems,  increase the  demand  for  an  all-in-one  development  solution.   Quite a  few  approaches  to  solving  this  problem  have  cropped  up over the years, ranging from purely web-oriented solutions to something more akin to a native application.   React Native and Progressive Web App development are two different approaches,  both new and promising,  on this spectrum.   This thesis evaluates these approaches in a standardized way using the  ISO  25010 Product  Quality  Model to  gain  insight  into these  types  of  cross-platform  development  as  well  as  how well  such  an  evaluation  works  in  this  context.   The  results show that, while not a perfect fit, a standardized evaluation brings forward less obvious aspects of the development process and contributes with a helpful structure to the evaluation process.

Web applications are subject to intense market forces, fast delivery and rapid requirement and code change. These are the factors that make maintainability a significant concern in any and especially web application development. In this report we develop a functional equivalent prototype from an existing Angular app, using ReactJs and afterward compare their maintainability as defined by ISO/IEC 25010. The maintainability comparison is made by calculating maintainability index for each of the applications using Plato analysis tool. The results do not show a significant difference in the calculated value of the final products. Source code analysis shows that changes in data flow need more modification in the Angular app, but with the objective oriented approach provided by Angular, we can have smaller chunks of code and thus higher maintainability per file and respectively a better average value. We conclude that regarding the lack of research and models in this area, MI is a consistent measurement model and Plato is a suitable tool for analysis. Though maintainability is highly bounded to the implementation, functionalities which are provided by the Angular framework as a bundle is more appropriate for large enterprises and complex products where React works better for smaller products.