Recommendations For Managing IOS & Android Versions For Same Game

I'm wondering what the best practices are for managing IOS & Android projects for the same game.

I've tried searching but can't find any resources that describe what I'm looking for specifically. If you know of any articles, I would very much appreciate a link.

My project is already in production on the Google Play Store. Up until now, I have only created the Android version of the project. I'm wondering what my approach should be when I start building and testing IOS builds.

Do I clone the project and maintain an IOS version and an Android version? (Seems troublesome) If so, how do you go about maintaining them both? Git is a solution I suppose for the codebase, but what about the projects and the scenes etc?