Is there really a point to using the assitive touch button just to substitute the home button on the iPad though? I mean considering it has four/five-finger gestures to close apps and bring up the multitasking bar.I use the assistive touch button all the time to save wear and tear on the physical buttons. It works very well, but sometimes is in the way on the iPhone, no matter where you move it to. Fortunately, the assistive touch button moves with a touch or flick to get out of the way. Less of a problem on the iPad where the screen is so much more spacious. Can put it in the lower corners.
In my experience, the Assistive Touch rotate screen buttons do not lock the orientation unless Portrait Lock is on. If Portrait Lock is off, then the Assistive Touch rotate screen buttons will rotate the screen as indicated, but physically rotating the phone will still cause the orientation to change.Lock the screen orientation. Set Assistive Touch to On. Then set Triple Click Home Button to Assistive Touch.
Now in any app that supports landscape triple click the home button and select device, then rotate screen, and finally choose left or right Landscape and it locks the screen into that orientation. It even overrides the portrait lock. Triple click the home button again to make the Assistive Touch icon disappear. It stays locked. Great for iBooks and Safari in bed.
Also you can move the Assistive Touch icon by dragging it if you want to keep it on the screen.