How do I add graphics to a c++ app

Answer 1

SDL is one of the more simple ways to add 2D graphics.
DirectX or OpenGL if you want 3D

Answer 2

you can also try Qt :)

Answer 3

SDL is a library you can add and use,
tutorials here: http://lazyfoo.net

There is also Qt, it is easy to learn, and good for apps like chatrooms(telegram used Qt)

these are some I know and worked with, there should be a lot more...