An HTML5 game programmer can use an accelerometer (the Accel object) to read tilt and movement input on supported devices, such as tablets and phones.

accelName = new Accel() Creates a new Accel object called accelName.
getAX() Returns rotation around the X axis as a –1 to 1 value (often used to modify DY).
getAY() Returns rotation around the Y axis as a –1 to 1 value (often used to modify DX).
getAZ() Returns rotation around the Z axis (rotating the device like a steering wheel). Typically, the getAY() also returns suitable values for this type of input, so getAZ() is rarely needed.
getRotX(), getRotY(), getRotZ() Returns the current change in rotation around each of the axes. Normally, the get() methods are more useful.