In preparation of using the Raffle App, the raffle organizer will give two pieces of information to everyone who wishes to participate in the raffle: the organizer's phone number and a code. The raffle organizer can distribute this information by either sharing them verbally or writing then down for everyone to see. The participants will then send a text message to the raffle organizer's phone number with the code typed in the body of the text message. When the app (running on the raffle organizer's phone) receives all of the text messages containing the code, it will save the all the senders' phone numbers in a list. Then, the raffle organizer will click on a button to randomly select a winner from the list of phone numbers. The winning phone number will be displayed on the raffle organizer's phone screen, and the app will also send a text message notification to the winner's phone indicating that he or she has won. Meanwhile, the app will notify...