How to extract apps in our device Android ?

Sometimes we find ourselves in need of an application while no Internet to download this application as it was already installed before.
Sometimes we want to send
an application to someone who does not have the Internet .... Also, we often install applications in promotion, then uninstalled its, and the day we want to reinstall it we find them pay again.
The solution APK Extractor, the application that is extract any application (system or normal) installed in your device an APK file to install it directly.