Hi, I was asked to give a recommendation for a communication platform for event / project organization. It needs to be
- available for desktop and mobile devices
- usable for non-technical users (think Whatsapp)
- privacy respecting (therefore open source and self-hosted)
So far I've heard of Matrix, Mattermost, Zulip and Rocketchat, but Zulip is the only one I have used myself.
Could you tell me about your experiences using these or other apps?