Xposed is a framework realized by Rovo89, a user of the famous XDA forum, can be installed into devices running Android (version 4.0.3 or later), and root access is required.
Xposed offers a structure (so called framework) where other users can develop system modifications, optimizations, add features, etc…
These are called modules (all are listed in the site, actually they are over 480) and can be used after installing the framework.
The big advantage is that they often use low memory and battery than the normal apps.
Xposed installation guide
The installation of the framework is very simple.
You just need to download the apk from the site, install it and give root permissions, then press a button and restart the device.
Modules installation guide
The installation is very easy too.
You just need to download the apk from the web site or inside the Xposed app – “Download” menu, install and enable the modules in the framework, then restart the device.
As said there are many modules, here is a list of the most used:
GravityBox – allows to customize the device (eg. change statusbar color, icons etc…)
Xposed Preference Injector – move all Xposed modules inside device preferences
Greenify – enable to access the experimental features of Greenify, the famous app dedicated to save battery
Xposed Call Blocker – allows to block numbers of unwanted calls
Xblast Tools – allows to customize anything in the device
Wanam Kit – another module to customize own device
App Settings – allows to change settings of the apps (DPI, rotation, etc…)
Xposed Additions – configure option that allows to remap hardware buttons
RootCloak – allow ticked apps that the device seems like non rooted
Fake Wifi Connection – allow ticked apps to fake internet connection (wifi instead mobile)