Remind has a new feature out that allows chat. Here's a good blog post on how the feature can be used by principals ....
5 Reasons Principals Should Start a Chat
Using Chat in beta for the last two months has been amazing, and my mind has been running with so many different implementation ideas throughout my busy day as a principal. Smooth workflow is key to a principal’s success to help us focus on what’s most important — spending time with students and teachers!