“The Mac App Store is either superb invention or a missed opportunity, depending on your perspective. But it undoubtedly has one flaw: You can’t keep a copy of the installers for the apps you buy or download,” Keir Thomas writes for Mac Kung Fu. “Apple expects you to be connected to the Internet if you need to reinstall in future – and that’s not always guaranteed.”
“Downloading and keeping the installation packages offers more than simply being able to reinstall apps if you’re offline,” Thomas writes. “For example, you can keep older versions of apps so that you can reinstall them if a newer version proves buggy, or simply doesn’t work how you want it to.”
Thomas writes, “To download and keep the installer packages from the Mac App Store we’re going to use a script created by developer maxschlapfer called – appropriately enough – AppStore Extractor Script…”
Links and complete instructions here.