SimpleConsole is the name of the example application inside of joan. It creates a remote version of the console known from the dedicated OpenTTD server.
SimpleConsole requires a properties file to configure it
host = localhost port = 3977 pass = <as configured in openttd.cfg> loglevel = info
Save the above configuration in a file, e.g. local.cfg
You can create multiple configuration files and use them depending on which server you want to connect to.
SimpleConsole is executed with a simple java command
java -jar joan.jar local.cfg
<config file> can be one of your properties files, e.g. _local.cfg as mentioned in the section above.