Laravel routing to class in app folder

I have a class in app folder with some functions used in many controllers. I have one function which i need to call from Ajax, but I don't know how to create the route to my class. My class is in

projectFolder/app/MyClass

How can I define a route to this? I tried to define the route in routes.php but it looks for a class in Controller folder. Thank you!

via Chebli Mohamed