Can somebody tell me what this mode is? Look at the screenshot. Does this mean after I dial 911 and hangup, I can't send or receive calls anymore for 5 minutes. Can I call 911 back? Can I use other features on my phone, etc. I looked online and can't find a good answer
Yes, this is now standard for Android (at least for the last several phone's I've owned). It basically limits the phone operation to only 911 calls for a short time I case you have to call them back or vice versa. You can exit out of it early if you want.