Users messaging each other... OUTSIDE my app

Hi gang. I’m looking to provide a mechanism for users to message each other, but I DON’T want them doing it inside my app. I’m sure I could create the necessary data types and privacy rules etc. to set up a messaging framework inside the app, but I don’t want to do it for a handful of reasons.

My PREFERRED approach would be to let users connect with each other inside my app (i.e. become “friends”) and then allow friends to see each other’s external contact info - specifically, one or more purpose-built, widely-used messaging platforms, e.g. WhatsApp, Twitter DMs, Facebook Messenger, etc.

I realize there’s friction in sending users elsewhere to communicate with each other, but is anyone doing something similar? How’s it working out? Is there a particular platform of the ones I mentioned that is notably better or worse for some reason? Another one I missed? Any and all feedback welcome!