Who to activate video in mylk-vr in multiple samsungs devices an a arduino.

I need to active a video in multiple samsung devices and a arduino at the same time, and activate them Through an app all in the same time. I don´t even know where to start looking for it.

I found that you can run the mylk vr app with a bluetooth, but I don´t know if it works for multiple devices.

I already know how to connect an arduino via bluetooth, all I need is a bluetooth library that sends a signal to a bluetooth module

I need to manage the way to do this 2 things from a single app in android

Do I have to make the app in java? is the only choice?

This is the faq of gear-vr says it can be doned in some way but i don´t kow how to make the app or whatsoever.

I look forward to hearing from you.
Yours faithfully