Hide application from app grid?
It depends on the launcher you are using. The stock Samsung Galaxy S4 launcher (TouchWiz) supports it.



If the stock launcher doesn't have it, you can use Nova Launcher. It allows you to hide apps so you don't see them on the app drawer.



UPDATE #1: According to Izzy's comments below, the following launchers also have a similar feature: 


Apex Launcher
Go Launcher Ex
ADW Launcher 
ADW Launcher Ex