Are you going to upgrade your phone? Do you want to be able to roll back to previous version of updated application?
You need to save APKs of installed applications to external SD-card, Google Drive, or send them by e-mail or bluetooth!

That's what APK Fetcher Pro is for!

Extract *.apk files from installed applications. Launch, force close, save to local storage, send through network, view application details and more... No ROOT required!

NOTE: APK Fetcher Pro can't save internal data of your applications, such as preferences, notes, game high scores or other stats, sorry!