The initial experiment uses a publisher/subscriber model - the first device publishes a message, then the second receives it. Using Firebase, the first device is notified that the message was received and stops publishing. Then the second device publishes a message and the third receives it. This process is repeated until all 11 devices are displaying an individual letter of the overall message.
Further developments with this experiment will attempt to automate the process - perhaps there is a pool of devices and the primary device sends out (up to) 10 messages, each device receives the messages, acts on one of those messages, and then the users sort out the jumped letters to display the final phrase.