The longer I use the G3 the more I find and appreciate some of the software tweaks LG has made to Android. I recently covered one such feature called Guest Mode.
Another feature I recently discovered pertains to the volume buttons on the back of the device. Not only can they adjust the volume of both media and your G3's alerts, but those buttons also double as quick-access shortcut buttons when your device is locked.
Before you go pressing either button for an extended amount of time, unlock your device, hop into the Settings app and scroll to the bottom of the list. There you'll find and select the option titled "Shortcut key." If the switch located in the top-right corner is in the "Off" position, slide it over to "On."
Now lock your device and then hold in either button for a roughly two seconds. The volume-down button will launch the camera app, allowing you to quickly snap a photo. While the volume-up button will launch the native notes app on your G3. The buttons act as shortcut keys whenever the device is locked, regardless of the screens state of on or off.
Unfortunately LG does not give users the option to customize either action. Instead you're stuck with these two shortcuts. I have no use for the note-taking app, but I do, however, have a use for the camera shortcut. As such, I'll leave this feature turned on for the time being.
With any luck LG will allow users to customize which apps the shortcut buttons launch in a future update.