Every time you share your app with someone, a text message is sent out that includes the link that enables the person to download the app.
The same default message has been pre-populated to go out with every text you send. This is how it looks:
Editing the text is super easy to do if you want to customize the message. Add or edit the default text and click 'Update'. The live preview of the app on the right will show you how it looks!