I'm not sure about "jitter," but I believe what you are commenting on is the lack of frame blur, which I explained in the article. Basically, if you shoot at any rate, you want a 180-degree shutter angle, which equates to 1/60 shutter speed for 30fps or 1/48 for 24fps. You can lock that in with FiLMiC Pro, but that means you can't crank the ISO/exposure low enough on a sunny day, unless you use an external ND filter. The camera/software balances shutter speed and ISO to give you proper exposure. This means that without an ND filter, you get a high shutter speed, but individual frames are very crisp.
When people shoot 24fps footage with a professional camera/lens, they are used to this issue. They try to mitigate the apparent "strobing" of horizontal objects moving across the frame by using low shutter speeds (1/48) and very slow panning. If you watch any "standard" motion picture and analyze the individual frames as someone walks close past the camera, you will note that the image of that person is slightly blurred and not crisp. That's a result of a low shutter speed (180-degree shutter angle).
Many consumer video devices (phones, camcorders, etc) these days default to 60fps. This means that even though you have a high shutter speed and crisp frames, you have so many more frames. Therefore, this sort of "strobing" is less apparent. And, of course, more of that "soap opera" look to the video.
In the case of this footage, there are likely two other factors that affect it. First, it's all handheld without external stabilization, cage, or other type of rig. Getting good handheld movement using only the phone is a challenge. Second, the app has built-in stabilization, which I had turned on. This appears to create some aliasing and adds some sharpening. That's as compared with the iPhone's built-in camera app in the video mode. I did a test of the two side-by-side and FiLMiC Pro does a much better job than the camera app, but it isn't perfect. Trying to shoot handheld without the stabilization enabled is considerably worse.
I hope that explains it.