Gyroscope.userAcceleration
var userAcceleration: Vector3;
Vector3 userAcceleration;
userAcceleration as Vector3
Description

Returns the acceleration that the user is giving to the device.

The significance of this value is that the effect of gravity (which is also detected by the accelerometer) has been removed to leave just the acceleration from the user's movements.
	var forceVec: Vector3;

	function FixedUpdate() {
		// Apply forces to an object to match the side-to-side acceleration
		// the user is giving to the device.
		rigidbody.AddForce(Input.gyro.userAcceleration.x * forceVec);
	}
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Vector3 forceVec;
    void FixedUpdate() {
        rigidbody.AddForce(Input.gyro.userAcceleration.x * forceVec);
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public forceVec as Vector3

	def FixedUpdate() as void:
		rigidbody.AddForce((Input.gyro.userAcceleration.x * forceVec))