A tip Apple didn't tell us about saving our battery!
I'm sure since updating your phone to iOS 9 your phone has hit 20%, and you've noticed the new "Low Power Mode" feature.
This feature disables non-essential tasks and flashy visual effects that you don't need. It also stop turning your phone screen on every time you receive a message.
Now, you've probably only ever turned this on when you get asked, but you can have it on ALL the time!
Just go to Setting > Battery > Low Power Mode and turn it on from there. Or if you're loving Siri's new features, just ask him to enable Low Power Mode.
If your phone is charging, it turns off automatically at 80% but swipe to the left and you can turn it back on!
You're welcome, now go back to your day!