Singlelink

TL:DR: Doesn't get much better than this. Beginners can easily add links and colors & have a working landing page in less then five minutes. More professional users can add custom css & html to get the absolute best out of their page. Either way, it will look great, and they even give you the option to exclude any watermarks if you want the page to be strictly your branding. Not to mention it's both open-source & COMPLETELY free. Definitely plan on purchasing their higher (whale) tier when it becomes available, but there's an astonishingly large amount of customizability even in their free plan. Neutron Creative sure knows how to make a good program!