Android : Device yaw on Android

I want my app to work on both iOS and Android devices.

I need it to act like a compass when device lies on table, but without magnetometer - relative yaw is enough for me. I don't care about cases when device isn't placed flat.

In iOS I store reference attitude first:

motionManager = [[CMMotionManager alloc] init];
[motionManager startDeviceMotionUpdates];

...

referenceAttitude = [specific->motionManager.deviceMotion.attitude retain];

And when I need relative yaw, I take it this way:

attitude = specific->motionManager.deviceMotion.attitude;
[attitude multiplyByInverseOfAttitude:specific->referenceAttitude];    
return attitude.yaw;

How to make this in Android? In NDK there is file named android/sensor.h, but I am only able to get ASensorEvent::vector.roll which is rather rotation speed than angle, from queue and then calculate yaw this way:

yaw = 0;

...

yaw += ASensorEvent::vector.roll * dt;

This works okay on low rotation speeds, but it is very unaccurate. How can I get relative attitude on Android?