Canonical's Ubuntu operating system released an updated version of their Developer Preview, showing of a new feature, that basically dual-boots your supported devices back to Android.
Back in October we saw the company announcing Ubuntu 13.10 for supported smartphones, where today Canonical made available the new feature, that helps in switching between OS's with-in an application. To be clear, there is no more key combinations or commend line interfaces to jump between operating systems.
As said by the officials, an application on each sides, with a simple user interface will allow you to boot back or forth Ubuntu and Android. As we read on, multiple Android flavors are supported, with AOSP or stock, CyanogenMod and the installation of Ubuntu can be done on all versions available in the phablet-flash channels.
As a part of our disclaimer, we don't encourage you to flash custom firmwares to your smartphones, until your aware of the basic flashing process and it's related command line interfaces. Accordingly, from the words of Canonical, its is recommended to flash the operating system on to supported devices by developers who are comfortable flashing with their partition layout.
Source: ubuntu