Sedona - Compile Swift Program is a free iPhone app developed by Ketan Appa. This app allows users to write Swift code directly on their iPhone, iPad, and iPod Touch. It is designed to support the latest Swift syntax and is ideal for learning and testing code snippets.

Swift is a general-purpose, multi-paradigm, compiled programming language developed by Apple Inc. It is used for iOS, macOS, watchOS, tvOS, Linux, and z/OS platforms. Swift is compatible with Apple's Cocoa and Cocoa Touch frameworks, as well as existing Objective-C code.

The app offers several features, including the ability to compile and run programs, view program output or detailed error messages, and a custom keyboard for easy input of frequently used characters. It is optimized for connecting with external physical or Bluetooth keyboards. The app also includes an advanced source code editor with syntax highlighting, bracket completion, and line numbers.

Users can open, save, import, and share Swift files using the app. It supports File Sharing with iTunes Connect, AirDrop, and iCloud. Additionally, the app provides a language reference for Swift.

However, there are a few limitations to note. An internet connection is required for compilation, and the maximum program running time is limited to 20 seconds. Some file system, network, and graphics functions may also be limited. It's important to mention that this is a batch compiler, so interactive programs are not supported. Users need to enter the input in the Input tab prior to compilation if their program requires user input.

Overall, Sedona - Compile Swift Program is a useful tool for Swift developers who want to write code on their iOS devices and test their programs.