When you use the Check box tool in the Form Designer, it appears as a box that on mobile user devices can be ticked on or off…
However, on the iPhone and BlackBerry the Check box tool behaves a little differently.
Apple do not use a tick box on their official iPhone user interface. Instead, a slider function is used which is defaulted to On/Off.
On BlackBerry devices the pop up list shows the options Yes and No.
This should be considered when designing your forms by using questions that the mobile user will not get confused with and have answers that relate to the default device answers.