I don't know if anyone has used the gs5 but one of the features I loved from it was a quick pop up for sms that you could reply in and send off without closing the app you are in. It was very handy say if you are playing a game or don't want exit g+.
I know there are some apps on the play store called pop up but they are ugly and not very smooth. And when you reply in them it still shows as an unread on your messages. So all around they are far from perfect.
I was wondering if anyone had seen anything like this for xposed or maybe just a root app. Let me know if you see anything like this because I would love to have it on the m8.