'Research' is a metasearch engine written in OOP PHP with a responsive front end in Twitter Bootstrap v2
It's a small project so everything is in th eroot for easy access, but in a larger project or framework I would use templates and appropriate folders for classes etc.
In the meantikem find the core app in the classes.php file.
main.php executes the main program.
There is optional (turn on/off) file i/o w serialisation for data collection and debugging.
The app uses session states to record settings selectable from the options menu.