If you wish to send already installed an app from one Android smartphone to another, it is now possible with a new app. Instead of downloading an app from play store or searching for an installable .apk file, just transfer it easily with this app.
Even without root or need of any perquisites this app will help you transfer original apk files even without searching them as an app bundle (single application .apk file)
It is called as Bluetooth App Sender. It is also available at PlayStore.
If you launch BA Sender, all installed apps will appear in a list. If you hover on it, a pop-up will appear with the app details such as size, version etc. Activate Bluetooth and search for the device where you want to send the app.
Some games or applications are very big in size and downloading them from internet or play store is a real time-consuming work.
Bluetooth App Sender quickly gathers the files related to that app and send them quickly to another device.