Stuffed Parrot Solutions.
Wifi Stop Go Board Overview:

The WIFI stop go board is a app that runs on an Android™ device or Windows™ computer.  It allows the message displayed on the device to be remotly changed from any device with a web browser on the same network.  It has been designed in such a way that it will run on most old Android Devices.

Android™ Screenshots:
Download Windows   Download On Google Play