(Cofounder here.) That's our motion retargeting algorithm at work. It'll fit the smoothest motion to your recording. In this case a constant panning motion does the trick. You can get perfectly stationary, motorized-tripod-like panning shots, and dollies with Luma without any equipment other than your hands.

Is this a proprietary algorithm? Can desktop video editing software or plugins do it this well? I would love to have this as a quick drop in for Premier or Aftereffects.

Also, are there any plans for motion estimation for achieving super-slow motion, like Twixtor or Timewarp? That would be a neat effect for mobile video.

We developed this in-house. We use additional sensor data and fairly advanced optimization algorithms to produce these videos (all done in real-time on your mobile phone!) Due to the lack of sensor data, and subpar camera models, you won't get results of this quality with desktop video editing software like Final Cut.