The LG G3 is yet to be available in most of the major markets of the world but development for the device has already started picking up over at XDA forums. Developer p_toti has released the G3 TweaksBox module for the handset, which brings with it a plethora of customization options and completely eradicates the need of flashing a custom ROM. The list of features include the ability to modify the navigation bar size and icons, customizing the notification panel background, color and tiles, tinted status bar and more.

The full feature list of the module is absolutely gigantic to post here, so I am just listing down all the various areas of the UI it allows the user to tweak.

Tinted Bars MOD Status Bar Tweaks Navigation Bar Tweaks Ring Pad Tweaks Notification Panel Tweaks Quicksettings Panel Tweaks Recent Apps Window Tweaks Other UI Tweaks Calls tweaks Messages tweaks Lockscreen tweaks Notification tweaks Camera Tweaks Sound tweaks LED Tweaks Launcher Tweaks Misc tweaks

Since the module is still in beta, you might run into some bugs or graphical issues every once in a while but none of them should deter you from using the module on a daily basis. If you have already managed to get your hands on the LG G3, head over to this XDA thread for the full feature list and download link of the module. You must already have root access on the handset along with Xposed framework installed.