For mobile development, several programming languages and tools are recommended based on specific needs. For platform-independent applications, web apps can be created using Apache Cordova. Elm is suggested as a modern alternative for web app development, replacing traditional JavaScript, HTML, and CSS. For game development, the Unity game engine is highlighted, supporting both 2D and 3D games and utilizing C# and JavaScript for programming. For simpler projects, Processing.org combined with the Android SDK allows for easy sketch development on Android devices. On-device programming environments include Pythonista and Codea for iOS, and APDE and AIDE for Android, which support various programming languages. For iOS app development, Xcode is the official tool, requiring a developer license for app submission. Android development can be done using IntelliJ tools, providing a robust environment for creating Android applications.