The iPhone 6 might feature an Atmospheric Pressure Sensor, as new APIs were recenty spotted in iOS 8 reference data that could be related to this type of component.
These APIs were discovered by dedicated Apple site 9to5Mac and they include reference altitude data including one called "isRelativeAltitudeAvailable" that tells apps if a device "supports reporting altitude changes." For the iPhone 5s, the API returns no.
Sources at Apple stated that the company has been working on an updated version of the Compass app that includes altitude tracking.
iOS 8 is expected to hit Apple devices in the fall of this year.
The first images of what could be the 4.7-inch and 5.5-inch iPhone models were posted up on Twitter by tech insider Sonny Dickson earlier this month.
The pictures show both devices side by side, and from front and back angles. The phones in the images seem to support many of the recent rumors regarding the handset as they include the much talked about rounded edges and larger form factors.
Apple's normal release schedule usually leads to a fall launch for its flagship smartphone. It is unclear if the 4.7- and 5.5-inch models will launch at the same time as some insiders point to the larger version hitting stores in the beginning of 2015.
The 5.5-inch model is expected to be $300 on-contract, but that will not stop buyers from picking one up, according to analyst Raymond James Tavis McCourt.
He recently weighed in on the price increase for the iPhone during an interview with MarketWatch, and by basing his assumptions on the latest consumer data, he concluded that most of them would be willing to pay a bigger price for a larger handset.
"Our June consumer survey points to continued growth in the willingness of iPhone users to pay $100 more for a bigger screen iPhone, with now a full one-third survey respondents willing to pay $100 premium," McCourt said.