WhatsApp rolls out a guest calling feature letting people join a call even if they don't have an account; guests cannot start a call and have to be invited (Anna Washenko/Engadget)

Anna Washenko / Engadget:
WhatsApp rolls out a guest calling feature letting people join a call even if they don't have an account; guests cannot start a call and have to be invited  —  It's also working on calendar integrations for later this year.  —  WhatsApp is adding more flexibility for talking to people who aren't regular users of its service.