My son went to Gems Cambridge International school (http://www.gemscambridgeinternationalschool-nairobi.com). They used a tool called d6 school communicator to send messages from school to parents (http://www.school-communicator.com/howitworks.php) The school is able to publish communications that are general to all parents, or specific to year group or class. Parents then customise information that they see. The app is available on desktop and mobile, with pop-up notifications for any new information posted. I found it to be useful in keeping track of school information and assigned homework.
My thought on this tool is it has potential to be extended to make it a two way communication, with the parent able to respond or initiate messages. The messages can then be directed to a particular teacher. The advantage over email is ability to keep a record of communication between parent and school. I see this becoming more useful where the parent is separated by distance from the school and cannot have face to face interactions. They can request for meetings on calendar.