This latest version from Canonical can be considered stable
Alongside Ubuntu 13.10, Canonical has also announced that Ubuntu for phones is now available for download.Better known as Ubuntu Touch, the new operating system from Canonical is based on Ubuntu 13.10 and provides basic services for a limited number of devices, which include Nexus 4 and Nexus 7.
Users can expect to have a limited functionality from Ubuntu Touch, but all the basic features are present: make and receive calls and messages, a number of applications, an agenda, and a few others.
“These apps complement the offer of pre-installed software on the phone, including Dialer, Messaging, Browser, Camera, Gallery, Notes, Contacts and a set of webapps such as Twitter and Facebook,” reads the official announcement.
The installation of the new operating system is not as easy as that of the normal Ubuntu, but with the wiki provided by Canonical everyone should be able to get it to work.
You can also download the latest Ubuntu Touch 13.10 images from Softpedia.