In the hopes of finding a messaging alternative that would work as smoothly as iMessage once did, we both downloaded a slew of apps that promised to help bridge the chasm. We tried everything:WhatsApp (nope), Slack (felt too professional) and GroupMe (two does not a “group” make) were all installed and then quickly deleted. We settled, begrudgingly, on Gchat, which remains to serve its purpose.
When a New Cell Phone Almost Ruins Your Relationship
Caroline Moss

Didi you tried telegramm? It works pretty good in iOS, macOs, Win, Android.