I just started using Whatsapp for a local organization that I belong to. This app may have been discussed earlier. It seems decent and easy to use once you are signed up.
It is easier on a phone or tablet. More confusing on a computer. Get the appeared, sign up but give them as little info as possible.
Then you can search for topics and or people to follow. There is aquill like icon to write a message. Topics can be preceeded by an @ or a # . Such as @orngbrl2 (Delco Bobby) or #Dynamax. It takes awhile to get the hang of it.