If using the native camera app with the OM2, will the functions on the handle still work to control the camera? I'm talking about the shooting button, zoom, etc. I'm using a Note 8.

I think you mentioned to the HID feature. If you want to use the local camera to shoot videos. Here are some process:
Mount the mobile phone to the Osmo Mobile and balance it.
Power on the Osmo Mobile.
Enable Bluetooth on the mobile phone.
Search and connect the Bluetooth and launch the pre-installed camera app or third-party app on the mobile phone.