I have no experience with them, but I believe what you are looking for is a wysiwyg (what you see is what you get) web builder. Hope that helps finding something.
Use mobrise tool, that helps you to create static site using drag and drop.
You can use static site generators - just google there are plenty of em.
You’ll have a job, most options are equally awful because it’s not a simple thing: you’re asking for a general tool that will work with a specific backend you want to build. If you want to create native clients you’ve actually got an easier job of it, because you can use a GUI toolkit. But web doesn’t really have that, there are a lot of toolkits but they all necessitate wiring up to a much greater degree; there are too many different things you can do for there to be a simple solution. This is why stuff like Bootstrap exists: it doesn’t remove the need to code some HTML/JS, but does allow you to build a web client by just using the defaults and following the instructions. Red Hat’s (ugh) PatternFly and Palantir’s Blueprint have tried to do more, still not drag and drop though. You can get drag and drop stuff, but it’s normally stuff companies have built that’s tied to a very specific backend, and most attempts die very quickly