The welcome screen is the first real bit of configuration. It's the first thing your patients will see when first approaching the iPad. The first row under the "check-in" section is where you'll configure the welcome screen.
The heading is displayed in large text and animates between the comma-separated words. With the configuration above, the heading will say "Hello", then "Hi there", then "Check in", and so on. These should be short, quick words that are easy to read and that will gently grab someone's attention. Feel free to change these or add more to your liking.
The message is displayed in smaller text and doesn't animate. You use this as a place to provide more info once you've gotten the patient's attention to explain what they should do (i.e. check in).
Here's how the above configuration will look on the welcome screen: