The remote bluetooth shutter & volume toggle functions are present but are not “perfect” yet and still under development.
For now, here is what to do to make it work:
1. Make sure that the the volume on the device, before opening the app, is not at its maximum or minimum.
2. Make a fresh start of the app. After the app is running and you put it in the background, it stops working.
We are currently working to improve this in a future release, coming very soon.