Sony reintroduced its Bootloader Unlock tool with improved usability. It is now more easier and requires only 3 steps to unlock an Xperia Android smartphone. Sony is indeed one of the few companies that officially supports unlock bootloader. It has its own website for the service.
To install custom recovery, custom ROM or apps that require root access, you should first unlock the bootloader of your Android device, if it is a non-Samsung device such as Sony and HTC (international Galaxy devices come with an unlocked bootloader). By unlocking bootloader anyone with the proper skills can modify and enhance their Android phone.
If you are one of those who like deeper customization on their Android device and want to install custom recovery or certain powerful apps that requires root access, you should first unlock its bootloader, if it is a non-Galaxy device such as Nexus. Here is how to unlock bootloader on Google Nexus 5.
If you want to install custom ROMs, mods or certain powerful apps on your non-Galaxy devices such as Google Nexus, Sony Xperia, etc. first you need to unlock its bootloader. Here is how to unlock bootloader on Google Nexus devices such as Nexus One, Nexus S, Nexus 4, Nexus 7, Nexus 10 and Galaxy Nexus.