Does any phone company besides Samsung offer a "pop up window" feature for their apps?

[AC Question]

With my Galaxy Note 3, I could open up a pop up window of Youtube, and play music from it, no matter what app I was running in the foreground.
This is different than dual window, because a lot of apps aren't compatible with dual window, but for example Youtube can be a pop up window over top any other app.
Is Samsung the only one with this feature? My Note 3 is broken and I am looking for a replacement, and I'm not too crazy about the Note 5 or the S7.

 

[ManiacJoe]

Is it really a popup window?
Or, is it just another app running in full screen mode like all app do?