Using this tool will restore the RootFS to its stock state and reset the user data. So creating a backup using iTunes before using it is recommended.
The Cydia version supports all devices running iOS 11.0 to 11.4 Beta 3.
The Jailed version supports all devices running iOS 11.3 to 11.4 Beta 3.
The 11.2 to 11.2.6 support has been added to the Cydia version.
The 11.0 to 11.1.2 support will also be added in the near future.
Although there's an option to not perform a full restore and keep the user data, I would really not recommend it, since it will leave a lot of left-overs from your jailbreak.