There are plenty of apps on Google Play for customizing your Samsung Galaxy S3 with wallpapers and new lock screens, but to be honest, you're not really customizing until you root.
Once you're rooted, you have unlimited mods and hacks to choose from to make your device run better or feel more you, and one of the easiest ways to find these customizations is with Xposed.
Created by by XDA developer rovo89, the Xposed Framework allows you to quickly search for, download, and install new modules, i.e. mods, onto your rooted Android device in a matter of seconds. In this softModder guide, I'll be... more