Google Voice will prompt you when a call punches through. Example, name of
caller is announced, with an instruction to press 1 to accept. If you don't
press1, call is sent to Voicemail. You can also set Google Voice to DISPLAY
AS YOUR ORIGINAL NUMBER such that when you make a call from your regular
number, it would display your Google Voice number to the call recipient.

Note: I've done this in Androidville, can't speak to anything revolving
around iOS!!!

Sincerely,
Olusegun
Denver, Colorado