hi can u guys please help me to create a ad network plugin for my game with different adnetworks supported in it , or is there already a doc which tells how to do this ?
old post, but there’s a free plugin include Unity、Vungle、ChartBoost、Admob for both Android and IOS.
you can direct use it or learn from the source code how to write plugin for you self.
Hello,
We can help you. Our plugin Universal Mobile Ads for iOS & Android is exactly what you need: Universal Mobile Ads for iOS & Android - Marketplace - Unreal Engine Forums It includes support for 15 ad networks (more coming soon) and Banners, Interstitials, Rewarded Videos. Plugin was released 2 years ago and was tested in many ways during this time. It’s stable, receives update every 1-2 months ,and we provide premium support.
If you have any questions, feel free to ask! 
Patrick,
gameDNA Ltd