When you have bought a popular Android smart phone like Samsung Galaxy then there are so many unofficial custom ROMs available for your phone. You can install these new ROMs, install new kernels, try out new recoveries and so on. But before you try the new kernel or recovery images, you should make a backup of your working kernel and recovery images. This way even if the new ones show some glitches, you can always restore the working ones from your backup. Of course, you can create a full ROM backup with a tool like Nandroid Backup, but another tool called Flashify allows you to backup and restore just the kernel or recovery (these two are the ones people experiment with most).
Flashify app works only on rooted Android devices. If your smart phone is not rooted, then you can try Kingo root to root your device easily. Though the main use of the Flashify app is to flash custom recovery images like CWM or TWRP to your phone, but you can also use it to backup/restore the existing recovery image.
In order to make a backup, switch to the Backup/Restore section in the Flashify app. Here you will see options to backup your device’s current kernel and recovery image. Touch the respective options to proceed with the backup of those items. You will be given the options to save the backup either in your local SD Card or on one the cloud storage accounts (it supports Google Drive, Dropbox and Box). As you choose the backup destination, it will proceed and save the backup there.
In the future, whenever you have to restore the kernel or the recovery, just go to the Backup/Restore section once again and choose the options to restore the respective items. As expected this will require one or more reboots of your device to complete the full restore of the kernel or the recovery.
Conclusion: If you experiment with your Android device’s kernel or recovery a lot, then it is a wise idea to keep a backup of the working kernel and the recovery. You can use Flashify app to backup and restore the current Android kernel and recovery images either on the local SD card or on one of the cloud storage accounts.
You can get Flashify app from https://play.google.com/store/apps/details?id=com.cgollner.flashify.