Assuming p2p, if the person is not in my contact list, then say it out to him/her. If s/he is, then whatsapp him/her the (further) details s/he needs. If I am in a professional setting, I just give my card.
I find this to be much much 'user-friendly" than any existing or possible app/software solution and call me a oldie but handing out a card makes me proud of sorts.
Edit : I apologize if this doesn't answer your question.
I made a button that I give to people in an email or text. It goes right in their phone. They never actually get my contact info but they can contact me anyways, with the button.
What?
ok, its not perfect yet but its getting there (i need asterisk, SMTP, and dns on the back end still). I call it a drop number (dropnumber.com) Want to be a co-founder? I'm piecing it together with contractors because I'm not super good at coding.