use speakers and headphones at the same time

NOTE* in the second method I think that the writer was confusing 'channels' with 'routes'. I have tested both with iPhone 7 on iOS 11. The best evidence I have to support my answer would that Apple states 'Important: The built-in speaker may be used only if no other eligible output ports (USB, HDMI, LineOut) are connected.' Also in the solutions posted here, neither method works. There seems to be no official documentation as to if it can be done (please update this answer if you find some). Is it possible? Probably, however Apple as of right now does not supply any way to do this. So after some further review, I would like to save everyone the headaches that I had to go through. If you need code let me know, but really I am just wondering if it is possible and what is the best route for doing this? The key thing is that I want to do it simultaneously. What is really strange is that I cannot find any official documentation saying whether this is possible only that 'The built-in speaker may be used only if no other eligible output ports (USB, HDMI, LineOut) are connected.'

Has anyone tried to play sounds through the speakers and headphones at the same time? Android + iOS IOS: Is it possible to send audio out both headphones and speakers at the same time? I have found a few other threads, but they don't seem to be working for me or they say you can't. Is it possible to play audio through speakers and headphones at the same time as of iOS 11? As of right now I am trying to find an app on the store that can do this, so far I have had no luck.

Use speakers and headphones at the same time