There is a way to do this.
For Simply Automated, with a computer at the network address connected to the internet, and using the UpStart software, one may manually turn on and off lighting, electrical circuits, or appliances using a smartphone that can access the internet.
Two programs allow the user to see and control that computer: LogMeIn.com or GoToMyPC.com. This allows one to see the program interface and manually turn on or off any station on the network. I have a scenario here in NorCalif where clients driving to their vacation cabin in Tahoe can manually turn on lighting and/or heaters in advance of their arrival by using their smartphone.
The downside is that the controlling computer must always be on and connected to the internet. Currently there is no direct Wi-Fi method to interface with a SAI network, but I know that SAI is working on a couple of surprise additions for their product line.