Answer without file rename
Note that an answer that does not require file rename is below.
Answer with file rename
OK, here is what I found, took me a bit of hunting after reading this post, so hopefully this answer will help everyone:
1.In the project contents pane at left, click the Folder icon.
2.Select the top-level blue line representing the project.
3.If you don't have the Inspector pane (right pane) open, click the button to enable it. This is the third button in the "View" toolbar towards the upper right corner.
4.In the Inspector pane, click the little folded-corner paper (file properties) icon.
5.First thing is Project Name. Type in a new one, you will be prompted to rename project content files.
I should add, this will leave your old app with the original name in the simulator, so you still need to delete it from the simulator. Also any files you created in the old app bundle will not be brought forward to the new bundle (unless you find them in Finder and move them over).
(EDIT:) One more important note. Renaming your bundle will mean that the App Bundle Identifier you registered with Apple Provisioning Portal will no longer work for that app. You will need to generate a new App ID and Provisioning Profile in order to distribute your app to a physical device.