The group I currently play with uses a group chat over SMS/MMS. But I’m going to be DMing a campaign with an open table, so I need something more persistent and flexible. I’ve used Discord in the past but IMHO it has way too many features.
What have you used to keep in touch with your players?
WhatsApp to coordinate.
Discord for voice chat and sharing links etc.
Foundry for play.
Miro for “clue board” when playing investigative games.