Flight is a fast, simple, extensible framework for PHP. It is quite versatile and can be used for building any kind of web application. It is built with simplicity in mind and is written in a way that is easy to understand and use.
Here's a short article on why you should use a framework. It's a good idea to understand the benefits of using a framework before you start using one.
Additionally an excellent tutorial has been created by @lubiana. While it doesn't go into great detail about Flight specifically, this guide will help you understand some of the major concepts surrounding a framework and why they are beneficial to use. You can find the tutorial here.
Learn how to autoload your own classes in your application.
Learn how to manage routes for your web application. This also includes grouping routes, route parameters and middleware.
Learn how to use middleware to filter requests and responses in your application.
Learn how to handle requests and responses in your application.
Learn how to send responses to your users.
Learn how to use the built-in view engine to render your HTML templates.
Learn how to secure your application from common security threats.
Learn how to configure the framework for your application.
Learn how to extend the framework to with adding your own methods and classes.
Learn how to use the event system to add hooks to your methods and internal framework methods.
Learn how to use dependency injection containers (DIC) to manage your application's dependencies.
Learn about the core methods of the framework.
Backwards compatibility has for the most part been maintained, but there are some changes that you should be aware of when migrating from v2 to v3.
There are some common issues that you may run into when using Flight. This page will help you troubleshoot those issues.