The ‘rolling shutter effect’ is not new within photography and is often regarded as more of a hindrance than an effect, but it can produce some interesting videos in the right situation.
This one shows the rolling shutter effect in action when guitar strings are being played (although it should be noted that the video does not accurately depict how guitar strings vibrate)
The rolling shutter effect occurs when a CMOS sensor is being used to capture an image. The majority of high-end smartphones include a CMOS sensor at it allows for versatile features such as fast burst mode and slow motion recording and also takes up less processing power than alternatives.
A CMOS sensor works by scanning each frame from side to side in a sweeping motion as opposed to capturing the entire frame in one go (as would be the case with high-end cameras). More processing power is required to process an entire frame, so by capturing the frame in stages (e.g 1/100th at a time) less memory is required.
However, when capturing extreme conditions of motion or fast flashing light, a CMOS lens can cause the rolling shutter effect to occur. In the cases below, this creates some nice looking visuals, but it can also cause annoying distortions of videos at photos at other times.
This video does a good job of explaining with visuals why the rolling shutter effect occurs:
How to prevent rolling shutter effect
In some cases the rolling shutter effect will be nearly impossible to prevent, such as those when you are capturing extreme motion in a repetitive cycle. However, you may be able to address the problem in some situations by steadying the camera as much as possible and increasing the frame rate (this may involve reducing the resolution of the recording if the setting is available).