You can create a simple "hello world" application using Interplay.
Start with an Http node (get) request, name the URL click on done and click deploy.
Also add a Http Response node along with a NodeJS Function node. Connect all nodes.
Click on the NodeJS Function node add msg.payload = "Hello World" click on done and click on deploy.
To test if the Hello world application worked go on the browser and type
https://(Instance Name).interplay.iterate.ai/(Get request name)