So you want to learn how to scroll text messages on your bag? Adafruit has published a guide that shows you how to make your own SMS-scrolling messenger bag. You are going to need a Flora, Fona cellular module, GSM antenna, flexible 8×32 NeoPixel Matrix, 2500 mAh battery, and other parts to get started.
The above video shows how this SMS-scrolling messenger bag works. More information is available here.