Nexus 5 Camera Improvements
The Android 6.0.1 update brings at least one major change to the Nexus 5 camera and it's one reason why you'll want to at least consider downloading the Android 6.0.1 update.
Once you get the Android 6.0.1 update on board, double-tap the phone's power button. This will now instantly launch the Nexus 5's camera giving you quick access to the app in times of need.
This works when the Nexus 5 is on or when it's in standby. It's one of our favorite Marshmallow features and it's finally here for the Nexus 5. (At first, it was only available for the Nexus 5X and Nexus 6P. It's now also available for the Nexus 6.)