I know this isn't an established UI convention, but hear me out. Currently, the Call Screen gets dismissed whenever you navigate away from it. This necessitates the user swiping down from the top of the screen, tapping Callscreen, and then waiting while it launches to restore it. I'd like to see (an option perhaps?) the Callscreen instead be a "Sticky" card that can not be dismissed while the call is active. In this manner, the user can switch to the Homescreen or another app without issue, and easily go back to the callscreen by using the Card view. In another case, say the user has the Notes app open and wants to reference something to tell the caller. They can simply swipe right to the Notes, read the info, and then swipe back. This workflow is much faster than the current method to invoke the callscreen once it has been dismissed.
Redirecting to Carrie.
Yes, this is really a good suggestion. I've noted it down and will take it into consideration while I'm currently doing the redesign thing. Thanks!