Thanks to Nick's Space Bubble Source Code, I created this test NIB-less project with 4 simple views. As shown below, the Main one has 3 buttons, click on any of them will trigger the switch to one of the 3 child views - each have a different background colour, and only have one button to close the child view and return back to the main view.
Please let me know if you found any problem (memory leaking?) or need further information.
Source Code for Multi View Switching Project (Updated)