This document provides an overview of hybrid mobile apps. It begins by discussing global smartphone market shares and mobile app development approaches. Native apps are explained as binary files that can access all device APIs but require platform-specific SDKs. Hybrid apps combine native development with web technologies, allowing a web app to run within a native wrapper that provides a bridge to device APIs. The document outlines the skills, frameworks, architectures, advantages and disadvantages of hybrid apps, and discusses challenges around UI design and cross-platform compilation.