Hi,
For a long time, I was trying to find solution to establish VPN connection between Apple iPhone/iPad devices and ScreenOS SSG devices, but without success. Now, with latest Apple iOS improvements, and support for IKEv2, it is possible.
In attach, I am uploading document, based on my lab tests, so I hope that some of you, that are using Apple smartphones, will be now able to access your corporate network, behind Juniper SSG devices.
Have in mind, that you should have Apple iOS 9.x installed, and need someone with Apple MAC, in order to prepare Apple VPN profile. More details in attached PDF.
Marcony