I recently took advantage of openWebPage to troubleshoot some issues I had on a real device when making a web request with makeWebRequest.
The problem I had was that I received unexpected data from the response which my code didn't handle properly. What complicated matters was that the url for the request contained dynamic query string parameters, and therefor it was difficult to reproduce the issue in the simulator.
openWebPage sends a notification to your phone to open the url in a browser on your phone. This way you can see the actual data being returned for the exact same url that you are using in makeWebRequest. You can then use this data in a test and fix your code accordingly.
This is a great timesaver! Let me know if you find this useful too!