This document discusses apps and Joost Nuijten's work developing apps. It describes several apps Nuijten developed, including apps for Eurosonic/Noorderslag music festival, Picnic festival, and ABN-AMRO Markets. It provides details on the development timelines and budgets for these apps, as well as the number of downloads. The document also covers app publishing on Android Market and Apple App Store, and notes different business models for apps including free apps with in-app purchases and the "Gillette model". It concludes with 5 key points to remember about app development.