iPhone 6 contains both a accelerometer and a combination gyroscope-accelerometer

Chipworks:

The integration of two accelerometers into the iPhone 6 is another example of Apple’s elegant engineering. The phone would have worked with just the InvenSense device, but since not all applications require the higher sensitivity and full six-axis integration, Apple added the Bosch device, which allows them to lower the power consumption while still providing a good user experience.

 

That's attention to detail. I wonder if any other smartphones use this approach.