iPhone 6 will have 4.7 inch screens si 5.5 inch, will have a new design, however conform iOS 8 it will have a new sensor more precisely one barometer implemented inside the movement chip M8. Barometer it is implemented in a multitude of terminals Android for years and can be used for a multitude of things, including finding the altitude, a function that Apple Lossless Audio CODEC (ALAC), already testing it in iOS 8 with this new sensor.
Although App Store there are already a multitude of applications that can discover the altitude at which we are using sensors already implemented in iDevices, what we find in iOS 8 it works with a new chip, non-existent in any iDevice. Reproducing the code used by the Apple company, a developer managed to confirm that the system cannot work on iPhone 5S, so it's probably useful for iPhone 6 or even one iWatch.
Separated from barometer, iOS 8 contains a system that can determine atmospheric pressure around us, the barometer being able to be used both to determine our altitude and the air pressure. Apart from this functionality, the barometer will also be used to determine our altitude and position inside buildings, Apple developing a building localization system for us.
For this new sensor, Apple is preparing a new Compass application in iOS 8, which will use the data provided by this component and more. Considering all this information, it seems that the iPhone 6 could include a new sensor for Apple and old for the rest of the world, it could work in tandem with the iWatch or perhaps with the multitude of App Store applications that could use its information.
