Google's Nexus devices are very versatile, in the sense that 3rd party development for these devices flourish. Ubuntu Touch isn't the only 3rd party OS available for the Nexus 4. The 2012 flagship, made by LG, and powered by Qualcomm's Snapdragon APQ8064 quad-core chipset, now supports Jolla's new Sailfish OS. The installation process is simple and takes just 2-3 minutes. Sounds neat, for installing a whole new OS on your Smartphone.
Jolla will be adding official support for several other devices, and perhaps the entire Nexus lineup. In which case, we would love to see how Sailfish OS behaves in a tablet, say the Nexus 7.