Canonical's final goal is to achieve complete convergence of its operating systems, and the devs are close to making this happen.
Ubuntu's Community Manager, Jono Bacon, has demonstrated in a short video how the complete convergence of an application, at code level, looks in an Ubuntu system.
The app he chose was Karma Machine, a Reddit client written using the Ubuntu SDK. In principle, developers writing apps with the Ubuntu SDK will be able to run the products on PC, phone, and tablet, without having to modify the code.
The application interface is also adapting to the display it's being used on and features different options that change to reflect the platform.
Canonical is trying to do the same thing with its Ubuntu operating system. In the near future, the Ubuntu developers will be able to write apps for a single OS that will be compatible with a large array of devices.