Can you teach me something I didn't already know about the iPhone 6 plus?

I just want to learn more about my phone, comment anything you might think i don't know.

Go to TIPS on your phone (it's an app, just search for it) and you will learn a lot.

You can use a code to see the actual signal strength rather than just relying on display Bars.

Enter Field Test Mode. To do this, you'll need to open up your Phone app and dial the following number, *3001#12345#* , including the asterisks and hashtag, and tap "Call."

I know all the tips but i just was wondering if there were any cool hidden features that i could enjoy a lot more!