This document provides information about building mobile apps using the Salesforce1 platform. It discusses how to create both customer-facing and employee-facing apps using out-of-the-box functionality, custom apps and integrations, Visualforce, and connecting to external services. Visualforce options for mobile include pages on record detail, publisher actions, and formula field links. The Salesforce1 app and platform allows for fast non-programmatic development while also supporting more advanced HTML5, JavaScript, and CSS-based Visualforce development.