This version removes the requirement to run an exploit.
Once you install this application via Cydia Impactor or something of the sort, SSH into your device and run the following command:
sh "$(find /var/containers/Bundle/Application | grep RootlessInstaller.app/install.sh)"
Due to a bug in rootlessJB (which will be fixed soon), you'll have to run a certain command (not the one above) every time you jailbreak or the app will crash, the install script will tell you which command this is.