If you've hacked around with a bootloader-unlocked Sony Xperia phone at any point, you may be familiar with the unofficial Xperia Flashtool maintained by the forum denizens at XDA. The app allows Xperia owners to flash firmware packages to their phones in a similar manner to the ODIN utility that works with Samsung phones. Now Sony Mobile has released an official app of its own to allow unlocked Xperia phone owners to perform these kinds of tasks.
An initial beta version of the Xperia Flash Tool is available to download now, and can be used to flash official firmware back onto an unlocked Xperia phone. Right now the number of supported phones is minimal -- three, to be precise -- but if you have an Xperia S, Xperia Arc or Xperia Arc S, you should good to go with the official Flash Tool. Additional devices should receive Flash Tool support in the months ahead.
You'll find a quick overview of what the Flash Tool can do in the video above, and more details over at the source link.
Source: Sony Developer World