How to Copy Android Application From Another Android Device

There are two ways to install Android applications : online and offline. Online by going to the Android Market or Google Play, then select the application and Install it.
Offline install : we've got the installer file before, the name is  APK file (Android Application Package), then we execute / run the APK file to start install it.

In this post will tell  How to get the APK file  from android application already installed on an Android device or tablet, so the file(APK) can be used as a backup or to be copied or installed on other android devices. 
For example, your friend wants to copy an existing application from your Android tablet, you just send the APK file, sent via bluetooth or copy to USB, then your friend will install using offline mode on his/her device. 

There are many Android softwares / applications for android that can easily get the APK file from an application already installed, one of which is the File Expert. File Expert  is very easy to use and not complicated.
File Expert not only to backup the APK file, but many other functions, as the file explorer, install / uninstall programs, theme manager, etc. 

To install  File Expert,   Go to Android market / Google Play, then do search  by using keyword File Expert, if you have found, download and install it. Or to get the it's APK go here

Once installed File Expert, to create a backup file or  making APK from installed application :
• Open / run the File Expert, tap on  File Expert
click on image to enlarge

• Tap on the My Apps  

• It would appear the installed applications, select an application to be copied / created an APK,
(give a tick on the right of the application)
In the example I chose IP Calculator application to be made APK file

• Then select / tap  Backup, located on the bottom. Then APK file will automatically be created and stored in the  backup_apps folder

• To go to the backup_apps folder, 
 from the main page to My Files menu