In iOS it's possible to configure a Selection and Edit Menu. That looks like this:
Also, the API is displayed here: https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/AddingCustomEditMenuItems/AddingCustomEditMenuItems.html
So is this possible on React Native? I am building a chat app where we need to allow copying messages and also custom menu items.