This document discusses different approaches to mobile app development, including native, hybrid, and mobile web applications. It outlines the advantages and disadvantages of each approach in terms of development cost, code sharing abilities, device integration, user interface capabilities, deployment options, and other factors. It then focuses on multiplatform native development using C# and shared code across platforms as a way to reduce development costs while maintaining high performance, full device integration, and other native capabilities. Examples of apps developed using this approach at Capgemini are also presented.