Many of us app developers aren’t UI experts, and many of the projects we build don’t have requirements for a high quality UI, so we just slap together whatever we can. Which often looks like shit.
Twitter has spearheaded an open source UI toolkit, meant to kickstart the development of web apps and sites, called Bootstrap.
I’m using Bootstrap as a base UI for all my prototype projects. Bootstrap gives me a complete set of UI tools to start with, leaving me to focus on how the application works. When I’m ready to share with anyone, it immediately looks good, increasing the chance that my prototype will have the desired impact.