How to develop a public app

hello friends , i had create an app by ocdev , named -> abcd
now i want to show something from abcd , without login ( or on login page) ,
in tutorial , we have something in xml named "public"tag , that we can use it to access on app without login,
i used it , but again i dont have access on " oc/index.php/public/abcd"
what is solution ?
thanks a lot

You can try using the @Public annotation like here:

I'm not sure where exactly the route is defined but found this: