Remind opened their chat feature to all registered teachers. That feature allows teachers to have students and parents reply with text to their messages. Now that feature has been extended to allow teachers and administrators in the same school building to text each other through Remind. Remind allows you to search for colleagues using the service within your school building.
When I first heard about Remind's chat feature I was leery of it because I was concerned that students and parents would be messaging teachers at all hours of the day and expecting rapid responses. Remind alleviated that concern when I saw the "office hours" setting in the Remind chat service. "Office hours" allows teachers to specify when they will allow them to state when they will be available for messaging. Teachers can also pause or stop chat exchanges at any time. In the video embedded below I demonstrate how to adjust those settings.