LG G6 V20 G5 G4 V10 G3 G Pro 2 and G2 (supported devices given below) allows you to launch apps by holding the volume buttons when the phone is locked. With Key Plus for LG you can choose which apps to launch including a built in flashlight.

Features:
✓ Configure separate events for Volume Up and Down buttons*
✓ Built-in flashlight allows you to toggle your camera flash just by holding the volume key without unlocking the phone
✓ Turns off flashlight automatically in a few minutes (up to 60 minutes based on your choice) to prevent battery drain due to pocket activation
✓ Launch any app on your phone
✓ Launch an "Ok Google" voice search prompt
✓ Supports Launcher Shortcuts as well. You can Direct Dial a contact start Google Maps Navigation to a preset destination open a bookmarked site and more.
✓ Root access NOT required
✓ No ads. Completely free with optional donation via in-app purchase

* Volume Down button action customisation is not supported in Android 5.0 and above due to restrictions from LG. Volume Down will continue to launch camera.

Requirements:
✓ Stock LG ROM (or ROMS based on it)
✓ QuickMemo installed and working properly
✓ Not compatible with Quick Circle case

Supported Devices:
All variants of LG G6 V20 G5 G4 V10 G3 G Pro 2 G2 including carrier specific versions of Verizon AT&T Sprint T-Mobile others and mini models such as Beat Lite Stylus Dual and more

Developed:
By Naveen Naushad for AppTuners

Disclaimer:
This is NOT an official app from LG Electronics. Key Plus has been developed by AppTuners for selected range of LG phones.