To add a little to the speculation on Nunchi comprising of Hardware, Firmware, or Software, here is my take:

Hardware: Unlikely. From the SHM demonstration, there did not appear to be any modifications to the Motorola Handset. The handset case was intact, and there is simply not any room in the device to have made modifications. This handset supports both Bluetooth 3.0 and Wifi, so it is possible that there were some external devices, but I believe this is also unlikely. Would E.Digital want to market something that requires handset modifications? I doubt it. This would void the warranty. Replacement costs out of warranty are in the several hundred dollar range.

Firmware: Also unlikely. Although the definition of firmware has evolved over the years, it usually refers to the software layer that sits above the physical layer, but below the Operating System. In mobile handsets this is the responsiblility of the handset manufacturer, and any changes require review from the FCC, which can take time. Neither the handset manufacturer nor the Network operator (Verizon) would allow any modifications or additions to the firmware, as this can affect the Network, and interfere with other Mobile users.

Operating System: Again, unlikely. In the demonstration, the mobile hadnset was using the Android Operating System. This is given away free from Google to anybody. The handset manufacturer takes the virgin OS and modifies it to interface to the firmware layer, as well as makes modifications requiested by the Network Operator(Verizon). Its is possible to "ROOT" your handset, and install your own version of Android, and many people do this, but again this does void the warranty. Under the license agreement for Android, you cannot sell or profit from any re-selling of the OS.

Application Layer: Very Likely. This is the top level software that all "apps" are developed with. Google gives out a free SDK(Software Development Kit) that runs on a regular PC, and allows developers to create apps using API calls to the operating system. These API calls are at a high level and do not allow any control over network connection, reads/writes to flash, etc. But it does allow network communications to your own server(s), where you can store data, process algolrythms(as referenced by E.Digital), using standard network protocol through the API.

So I think it is likely that Nunchi is an app, communicating with the E.Digital servers, and the combination of the two are referenced as a "platform".