This constitutes the Remote Desktop app walkthrough. The resulting application can be actually used for simple tasks, for example, occasionally clicking on the Play button in iTunes or closing a program. More demanding interactions, in particular administrative tasks, may require much more complex software.

We also built a Flask-powered web server capable of dynamically producing images and interacting with the host system. On top of it, we launched a "light" JavaScript version of the app featuring pretty much the same functionality. The morale of this story is that our Kivy app does not exist in isolation. Far from it, in fact: we've actually had a server together with the working prototype of a client app—all before writing even a single line of Kivy-related code.

As a general rule, it helps immensely to build your software in such an order so that you can test every part of it immediately. I'm not talking about test-driven development (TDD) here, as it's arguable whether full-fledged...