RabbitHole allows you to connect your rcp-server to your rcp-client over the internet.
RabbitHole only relays data from your rcp-server to connected rcp-clients and vice versa. It does not store any data going through it.
RabbitControl is a protocol tailored for remote controlling your application. It specifies datatypes and ui elements and allows easy access to exposed parameters. You find more information here: http://rabbitcontrol.cc and here: https://github.com/rabbitControl/RCP
You can use RabbitHole to control your remote application over the internet. This may be handy if you need to monitor your application or you need to set some parameters while not on premise.
The public tunnel is limited in bandwith and amount of connections. It is intended for testing or a quick tryout. Be aware that using a common tunnel name may allow others access to your parameters, it is best to use a unique name with at least 4 characters. If you need a stable tunnel you can sign up, private tunnels have no limitations.