Building a web app from scratch is very hard and time consuming. You have to build user authentication, user management, permission handling and etc... by yourself. Maybe you don't want to build any of these things. You just want to build you business logic. Then the Appskull is the best solution to do that. Because Appskull is comes with lots of pre-built and well tested features. So you don't have to build those features by yourself. Instead you can focus on building your specific business logic with Appskull's all the bells and whistles.
Appskull can divided into two separate parts.
Appskull's front-end is designed by using Bootstrap CSS framework. For this reason, most of the people can easily extend Appskull's frontend very easily.
Appskull's back-end is developed by using CodeIgniter PHP framework. For this reason this app is very secure and very easy to extend to suit your needs. There are tons of free tutorials available online about CodeIgniter and how to use it to make great web apps.
As this Appskull application based on CodeIgniter, it's follows HMVC (Hierarchical model–view–controller) design/develop architecture. That's means it has 3 main different parts.
We use this architecture to organize our code well. It's help us to develop our app easily without worrying about the code scalability, code readability and etc...
CodeIgniter has one of the most easiest to follow documentations. You can get a really good idea about how CodeIgniter applications are organized and built within few minutes of documentation reading. So get started.