Here is a project of mines to create a hacker version of the beastgrip. The big change is really the handle of the device where I put holes to allow me to mount extra things inside and outside the handle. Also added to holes to the back of the clamp so I can possible mount a backup power bank that I can have connected to the phone to extend the time I can use it.

Just like the beastgrip you can screw in 37mm lenses to use with you're phone. I actually used a lens filter plus 3d printed a clamp to attach it to the rig. Works very well to replicate this feature of the beastgrip. If you do try to build this, get the cheapest filter you can. The quality of the glass isn't important, what you really want is the metal threading.

Thats about it. I have some ideas for the second version. Sketching some ideas of creating the rig a bit differently. Also will attempt doing something with thumb screws so it'll be easier to put the 3 main parts together. Also want channels or some way to easily run the headphone wire in the rig. So all in all, a good start but far from where I want to be.

I modified an open source camera app to use the earbud buttons but because of some issues I'm thinking about creating my own Android Camera app specifically to use with this rig. I've done a simple camera app before on android for work, so I'm confident I can put together a fun open source app for this project.

I'll begin work on MK2 once I finish my other project, a gimbal camera stabilizer. As you can tell, most of my projects are geared around photographing :)

Small Youtube Video about it.
https://www.youtube.com/watch?v=g6gWaz9hLuY

Freecad source included.