A little text field to leave a message in!
At first, you'll see the message left by the last visitor. If you'd like, you can replace it with your own message. It will be stored (thanks to MyJson) and shown to the next visitor.
You can see or change the message by clicking this link: https://navigatron.github.io/leave-a-message/
At first, my goal was to see if I could build this in 15 minutes. I got close! I had to take an extra 10 minutes (for debugging) in order to achieve functionality.
Total time: 25 minutes.
After the challenge was over, I cleaned the JS and added some CSS to make it look pretty.