Sony has started the upgrade to Android 4.4.2 KitKat software. The update is currently only live for the Xperia Z1, Xperia Z Ultra and Xperia Z1 Compact, however before you eagerly upgrade you should be aware of the limitations relating to microSD memory cards. In basic terms, when you upgrade to KitKat, third-party apps will no longer be able to write to SD cards.
What this means in practice is that, for example, you will not be able to use a third-party file manager app to copy files onto your SD card over a network. Another example is that you currently cannot use the TomTom app to download your maps to the SD card if you are on KitKat.
Only first party apps are able to write to the SD card, which is why the File Commander app will still work on Xperia handsets running KitKat. Third-party developers can get round the issue by creating a dedicated private folder on the SD card which the app can write to. A problem with going down this route though is that all data written to these private folders will be deleted as soon as the app is uninstalled.
Currently the only way to get round this issue is to root your handset and use an app such as “SDFix: KitKat Writable MicroSD“. However, as there are few rooting options for Xperia KitKat firmware right now, it is a moot point.
So despite most Xperia handsets offering microSD memory card support, it looks more and more that the only use for these cards will be to store photos and media. We don’t see Google changing its stance anytime soon, so we really hope that Sony starts shipping phones with higher storage. Flagships in particular should be running a minimum of 32GB in our view, especially with app/game sizes getting bigger all the time.