I get the impression that what this app does is create a placeholder website that just references (almost like an iFrame) a portal map stored at ESRI online. I'm REALLY hoping that this is NOT what is going on. I have downloaded the WebApp Builder, but haven't gotten it installed yet. My GIS group doesn't consider it mission critical so it's left to when I "have time" (which so far is never).
Could someone with more experience give me some feedback here?