how to make Android Multiplayer game via local wireless Wifi

I am looking for a way to making a cross platform multiplayer game using UE4 (4.12). my target platforms are Android+Ios+VR.(maybe Windows+Mac+linux)
(priority of target platforms: android,ios,oculus rift,Win)
so one of my favorite goals in mobile platforms is the connection of the players via local wifi like ShareIt application.
suppose that one device can be as the server and others can be as clients that connects to the server.
I think this is a little difficult and trouble by Unreal Engine 4 blueprints…
so is there any perfect tutorial or some suggestions to make it?
this part of my question is not important for me, just is for my knowledge improvement:
if i can solve my problem, is there any ways to having both local connection +internet connection via Wifi? because some games require to save information on a server so players can load their soldiers and guns data from server and then they will start their multiplayer match…
thanks a lot…

are you found any solution of direct wifi in android ?