What are some interesting but generally unknown features of the iPhone 6 ?

iPhone 6 interesting unknown features 

I was at the vegetable market when I took out my phone to check the time. What I saw was this:

Notice the bottom left corner of the screen. That's a calculator shortcut. It isn't present there normally, but was there at that time. Then I unlocked the phone and saw this:

At the bottom of the screen, there was again a calculator shortcut with the description "Based on your current location". I found it awesome that the iPhone could not only detect my location, but also knew about my needs, that I might need a calculator at the market. Cool, isn't it? :)

Edit: Some people in the comments section have pointed it out that this feature is creepy as it stores data based on our location and tracks us. So in order to disable these settings, go to Settings-> Privacy-> Location settings-> System services-> Frequent Locations and turn it off.