The iPad Air 2 and iPhone 6 have a built in barometer that can calculate atmospheric pressure. However, its sensitivity and accuracy are debatable.
The first iPod unveiled by Steve Jobs on October 23, 2001 was Mac-only. It had a 5GB hard drive that let you carry "1,000 songs in your pocket". The device cost a bit less than $400. The Windows iPod was introduced only 1.5 years later. [more...]