Bracket to attach smartphone to SJCAM gimbal in addition to SJ7 Star

I'm new to action cameras but I'm having a ball with my new SJ7 Star camera. I ordered a SJCAM gimbal but haven't received it yet. But, while watching some YouTube videos, I saw a setup I'd like to use. That is, while using the camera on the gimbal, also mount my smartphone to the gimbal off to the side and horizontally. That would make seeing what I'm shooting easier with the SJCAM phone app.

I realize the gimbal is new and not too many people probably have it yet but if anyone does and they have a mount to attach their smart View attachment 338 View attachment 338 View attachment 340 phone to the gimbal, I'd really appreciate knowing what mount they used. I searched for what I'm looking for but haven't found one that would work that well yet.

Attached are a couple of pictures of what I'm talking about. Sorry that the pictures aren't better but it should get what I'm looking for across. I have no idea what brand of gimbal is being used in the pictures so whatever phone bracket he's using might not work with the SJCAM gimbal but I'd like to get something similar.