I'm considering the Apple Watch (sport), but first need to understand if any 3rd party gym/weightlifting apps are able to use the watch sensors. Some articles say yes, others say no. Are there any gym apps that can use Apple sensors? If so, does the data collected from the app count towards your overall calorie burn on the Watch i.e. circles of health, etc? Can you please suggest any gym/weightlifting apps that you meet the above criteria? Thanks so much.