I have been testing alpha version of Draftium before the launch and must admit it has greatly simplified my work. So when I need to create a landing page, I make a quick wireframe (with copy) in Draftium and pass it on to UX designers. They already see what I want to get as a result and so we spend less time on numerous iterations.
I have yet to use it, but from the video alone, it looks like something to further speed our process.
Update: Loving this product. The makers are checking all the right boxes and what I love about it beyond the relatively generous free tier as well as the package this fits into, is the overall intent behind it. To cite a comment I made: "Absolutley love the motivation behind this: the combination of simplicity, speed and frictionless workflow paired with tasteful results," it just makes for an awesome combination not to be missed.