"Small" is an understatement. The Ubuntu Touch device list [1] lists a total of eight officially supported devices. The Nexus 4 and Nexus 7 are both out of production, and none of the BQ or Meizu phones are listed on their web sites anymore. The BQ Aquarius M10 tablet still shows up on their web site, but it's a tablet, not a phone.
So the short and the long of it is: Ubuntu Touch, as a phone operating system, is dead. It's probably not long for this world on tablets either, considering that the only supported device is a single product from an obscure Spanish manufacturer.
