The CP2130 is an easy to use USB to SPI bridge, Silabs gives the necessary tools to get it running in several OS.
For Windows, Linux and OSX we have dll that once installed the OS recognize the CP2130, and you can code your program to communicate with it using a set of functions given in those API. This is very usefull when using these OS, but what about when you want to use an Android devices?
The Silabs solution for Android is a little bit more complex, you can compile the linux library for cp2130 in the linux kernel that runs under the Android, hence, once compiled, your Android will recognize the IC, and then you can use the library functions when code your app. So, the way is always installing drivers or libraries in the OS, but the problem is that almost 100% of the android devices has no root permission by default, so this seems not to be a good option if you want to have a 'plug and play' solution for a comercial device for Android (rooting means special skills, losing warrannty...)
To avoid this issue, this answer is again in Silabs website, you can find the AN792, with the CP2130 specification, and with this application note and the usb host api in android sdk, you can get an app for any device which runs Android not rooted (minimum ICS), and with no-specific driver or dll for the CP2130, just install the app, plug the CP2130 and start communications.
See this two examples Using CP2130EK, an USB to SPI brigde, in Android (Part1) and Using CP2130EK, an USB to SPI brigde, in Android (Part2).
I really hope you enjoy this post,
Miguel