I tried the "on suspended" and "on resumed" with a simple textbox that set the text to "suspended" and "resumed" and it's works fine on IE and Firefox but not on iOS in Safari. :(
It would be really cool if Ash or anyone from the Scirra Team found a way to make it work in a future build! :)
Is there any other way to detects this, maybe something clever like getting the system time of the used app and comparing it with the time one second ago every second...?