Some conditions that could help:
(Compare two values)
Browser.ExecJS("navigator.platform.toLowerCase().indexOf('iphone') > -1") Not Equal To 0
Browser.ExecJS("navigator.platform.toLowerCase().indexOf('ipod') > -1") Not Equal To 0
Browser.ExecJS("navigator.platform.toLowerCase().indexOf('ipad') > -1") Not Equal To 0
Browser.ExecJS("navigator.platform.toLowerCase().indexOf('mac') > -1") Not Equal To 0
Browser.ExecJS("navigator.vendor.toLowerCase().indexOf('apple') > -1") Not Equal To 0
I used all the conditions together in OR condition to determine if I'm in iOS device, woked for me like a charm.
But for your need it should also work independently to determine exact device.