Earlier this month, I installed a new racing game on my Android smartphone, only to find out later that it contained the Leadbolt.E virus inside it. Although the Eset Mobile Antivirus caught the APK file in time, I still chose to restore my smartphone to the factory settings. But when the phone restarted after factory settings were restored, all the installed apps were gone. I had to go through the manual searching of those apps on Google Play Store and installing them one by one and it took a long time before I had all my usual apps loaded. Through this painful experience I have learned that you should always keep a backup of your installed apps ready, so that in case you have to reinstall them, you can just use the APK files from the backup.
The free App Backup & Restore app for Android can help you quickly backup all the installed apps to your external SD card very easily. And later you can also restore these apps with a single tap. As you launch App Backup & Restore, it shows you a list of all the downloaded apps found on your system (there is no point in backing up apps other than the downloaded ones). You can choose one or more of these apps that you want to backup. There is a convenient select-all checkbox, tapping on which you can select all the apps in the list. After this, you can tap on the Backup button and it will start to create a backup of all the APK files for these apps.
By default the backup is created inside a folder named App_Backup_Restore on your default storage SD card. You can open this folder to see all the APK files for the apps that you have created a backup for. You can open these files to install these apps yourself, but App Backup & Restore offers a Restore feature which is much more convenient. You can go to the Archived section of this app and select all the apps you want to restore from the backup. Then you have to tap on the Restore button and all the apps will be restored back to your phone.
In the settings of App Backup & Restore, you can choose if you want to override the older versions of an app (prefer older versions over the newer version of an app if available), number of versions to keep (it can backup many versions of the same app), choose a backup path, show system apps in the backup list and more.
Conclusion: The App Backup & Restore app for Android can keep backups of different versions of various apps that you have downloaded and installed in your smartphone. It is also able to restore these apps at a single touch of the screen.
You can get App Backup & Restore for Android from https://play.google.com/store/apps/details?id=mobi.infolife.appbackup.