wp determines which editor is served on any device… since we had problems with our version of tinymce working on mobile devices, we had forced it to be a plain textarea… when we switched to the wp built in tinymce version, wp already has tested and has logic as to which devices it works on… so we let their logic determine which editor goes on mobile devices…
In my testing on ipads and android phones… as well as with emulators that allow us to set the user agent string (that is how a browser identifies itself), it was working nicely… so yeah, on ipad you should probably get tinymce…
if you use that filter mentioned above, it will disregard what wp says and for any mobile device will force a plain textarea… the editor type of 4 means plain textarea…
As I mentioned in post, I had tested it, but didnt save my code so had retyped it… will try to retest it… but the other user confirmed it working…
you should be able to go to: http://whatsmyuseragent.com/
on your mobile device and it will tell you the user agent…
another test would be in your spFunction.php code that you put in to add after the global declaration an:
ashow($SFMOBILE);
and see if it thinks you are on a mobile device….