Mobile chat app
I'm looking for a chat app. I need a free mobile chat app where two people can hold multiple separate conversations simultaneously. I've tried several apps (Viber, WhatsApp, Teams, Messenger), but none of them allow creating a two-person group. I'd prefer free apps where the profile is linked to an email address or an account, rather than a phone number. Ideally, a well-known app, or at least a secure one, would be best. Could you recommend any?