Many different launchers will allow you to do this. I use next 3d and have all kinds of app resizing, rotation, background etc. This would affect your homescreen and lockscreen. Not sure if it affects the app drawer
If you mean the size of the icon that represents the app on the homescreen, some launchers let you do that. Install all the free launchers you want and play with them. You might find one you prefer to the one that comes with the phone. (The first thing I do to a new phone, other than conditioning the battery, is install Nova launcher.)
If you mean the actual size of the app files themselves, no.