Online Nandroid Backup is described as 'Nandroid backups are usually performed in recovery mode. This means you would have to turn off your phone and reboot in recovery mode, which wastes a whole lot of time rebooting and a lot more time offline' and is an app in the system & hardware category. There are 2 alternatives to Online Nandroid Backup for Mac, Windows, Linux and Android. The best Online Nandroid Backup alternative is TWRP Backup & Restore Tool, which is both free and Open Source.
This tool gives you an ability to make a backup of your phone to your PC using the latest TWRP 3.1.0 Recovery. This is a simple handy tool if you want to make a backup of your phone to your PC and you don't want to deal with ADB commands.
