Jaime Valencia gave the best answer he could here: https://supportforums.cisco.com/discussion/13124056/cisco-jabber-not-integrated-ios-10
I have heard that Jabber iOS 10.8 will include CallKit support, and that is due in very soon (end of quarter). ...
I can't see the document either, but I would guess with some certainty that this is talking about an upcoming update to the iOS app. Most likely takes advantage of CallKit, new to iOS 10; so you'll need to update your iPhone or iPad to iOS 10 as well
