How can I copy installation/setup files of an App downloaded from Mac App Store?

[samratm]

I just purchased and downloaded Xcode on my Macbook Pro and now want to install the same on my MacBook Air and iMac but I don't want download them again and again. Isin't their anyway by which I can copy the installation/setup files of that App and paste it on another Mac and use my iTunes account credentials to verify the App with Apple servers, so that they know it's legit install. And also keep that copy as backup so that, I can install that App again after I format my computer.

I live in a third world country and aren't blessed with high speed and unlimited bandwidth connection.

 

[samratm]

Got it

Issue solved:

Answer found in Apple FAQ's site: http://support.apple.com/kb/HT4482


The Mac App Store remembers all apps you purchase with your account. Apps you purchase and install from Mac App Store can also be copied to an external hard drive, USB Flash Drive, CD/DVD, or backed up via Time Machine.

If you save a copy of an app to removable media (such as an external hard drive) or file share, simply drag the app back from its storage location to your Applications folder. When you open the restored app for the first time, you may be required to sign in with the Apple ID account that was used to purchase the app.