Remind is probably my most used teaching app (besides maybe Google Classroom), and it’s the one I’ve found to be the simplest to implement and the most beneficial for communication.  It can be set up for communication with students and parents via email, text, or through the Remind app (mobile download). It’s basically set up the same as any other messaging app, but with some additional teacher-friendly features.  For one, you can set up classes to send messages to particular groups of students or parents.  You can also set up hours during which you can be contacted.  Messages can be scheduled to be sent out at a particular time, which is especially useful when I think of something I want to tell my students late at night or early in the morning.  One of the most important features is Remind’s automatic message saving, which saves all communications to an outside server, keeping all parties accountable during conversations. If you’re goal is to be accessible to students and parents (it should be!) this app is a must have.