This is the altimeter that will be able to function both out of the doors and in the doors. This altimeter can detect even the slightest change in altitude (Requires iPhone 6 or 6 Plus). When outdoors, the app functions just like a typical altimeter, but when indoors, where the GPS signal is weak, the app will still be able to detect the changes in altitude through the barometer in iPhone 6 and 6 Plus.
Other features include
1. Display in metres or feet
2. Barometric pressure