Technically, yes, We don’t have a smartphone app for this and haven’t heard of anyone developing one yet.
The firmware in our Waiter ECC circuit board is hard coded to search for and log onto the WaiterControl SSID. It then connects to the MQTT broker at IP address 192.168.50.10. which is part of the Waiter ECC touchscreen computer.
If you wanted to use NodeRed, OpenHAB, HomeAssistant, or develop your own application, its simple, connect your device to wifi network WaiterControl, and point your MQTT application to the broker at 192.168.50.10. OR, add a bridge to connect the WaiterControl network to your regular home network that has your NodeRED, OpenHAB, or HomeAssistant applications.
If you don’t want to use the Waiter ECC touchscreen hardware, You could build a Rpi as a wifi access point with the SSID name of WaiterControl, install a MQTT broker at a static IP address of 192.168.50.10., and set up the DHCP server to provide the control module with an IP address. You could then connect the WaiterControl network to your other networks using a wifi bridge.