What we have right now is a very barebones implementation of video stabilization. There are a few more things you can add to it to make it more robust, more automated and the output more pleasing to the eye. Here are a few things to get you started.
In this chapter, we've hard-coded the axes of the gyroscope. This might not be the case for all mobile phone manufacturers. Using a similar calibration technique, you should be able to find an axes configuration that minimizes errors across the video.
We've hard-coded the direction of the rolling shutter. Using specific techniques (like blinking an LED really fast at the camera), it is possible to estimate the direction of the rolling shutter and incorporate that into the calibration code. Certain camera sensors don't have the rolling shutter artifacts at all. This test can also identify if such a sensor is being used.