Lots of devices from low to mid-end range don't have gyroscope installed, and thanks to that have AR capabilities severely decrased.
I'm working on Xpose module that uses Accelerometer and Magnetic Field Sensor to simulate Gyroscope output....
It could be also interesting use the orientation sensor? In my moto g3 I have it, but I haven't got gyroscope.
Orientation sensor in general have the same functionality as accelerometer, but from what I've seen they have rather low resolution....