I have and app access barometer on iPhone and Ipad, when Apple release iOS 10 some iPad user report that app stop working. I tested on my iPhone 6s iOS 10 and it still work fine. Search Apple Dev, no API change. In the app i use below code to get barometer sensor information:
if([CMAltimeter isRelativeAltitudeAvailable]){ // This return false on iPad
[self.altimeterManager startRelativeAltitudeUpdatesToQueue:[NSOperationQueue mainQueue] withHandler:^(CMAltitudeData *altitudeData, NSError *error) {
if (self.delegate){
[self.delegate updatePressure: altitudeData.pressure.doubleValue*10.0];
}
}];
}