I spent some time today developing a rapid prototype of an app idea using Briefs, a brilliant open source framework by Rob Rhyne. I’ve only been using it for 6 hours, but I can already see it becoming an essential part of my design process.

I’ve been drawing flow diagrams, rough screens, building paper prototypes¬†(using my iPhone “template”, pictured above), but the benefits of being able to quickly test functionality directly on the device are huge – there is nothing like being able to interact with your sketches to get a sense of how the app will feel.

Briefs is a very clever idea – you write instructions in a simple CSS-like syntax (it actually reminded me a bit of my early days of timeline-based flash scripting), compile the actions and images using a command line tool and load them on to your device through XCode – what you get is a functional imitation of an app.

Because it’s basically just a list of images, links, and transitions you can use anything from rough sketches to fully fledged designs, all without having to invest the time coding – great for trying out screen flows and sequences without any risk.

In building my prototype today I’ve already identified a few flow issues that I missed on paper and that would have been much more difficult to change after implementation.

What I love about briefs as compared to¬†other similar concepts is the fact that I can test out ideas in extreme low fidelity – when I’m playing around at this stage of a project I don’t want to get bogged down in small implementation details or finicky design changes (that all comes later). I just want to know if I’m on the right track. For this purpose I actually find very rough wireframes more useful than hi-fidelity ones – it helps keep focus on the action (and interaction) instead of the superficial aspects of the application, and for working at that level of detail Briefs is perfect.