Sensor Core is part of the Chipset built into your phone. You do have it. It does, however, need several different pieces of software for you to take advantage of it. Motion Data may be in the App Store, but it really is a Setting. Go to Settings > motion data > make sure it is turned on.
Once it is enabled various Apps can take advantage.... For example once Motion Data is on, then the Health and Fitness App will start tracking your steps and you can use that data history.
What are you trying to do that you can't?
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