Background: I have written code in Python, C++ and Haskell for many years. However I have done no substantial web programming.

My goal is mathematics-education-themed apps to run on browsers on any device. At first I'll be happy to run the app on my laptop and connect locally with an iPad or smartphone while I sit with my students. 

Later I may deploy it at scale "in the cloud" (I mean anyone connected to the internet can run it, and the servers belong to the hosting provider).  

Why a browser app? I figure it's the best way to get a portable app that will run on phones, tablets, and computers of all OS's.

Why Haskell? The goal right now is fast prototyping and experimentation, especially for some fairly complex algorithms. I spent some time with JavaScript, TypeScript, and Scala.JS. I'm just so much more comfortable in Haskell with which I can write clean & sophisticated algorithms quickly.

I see lots of mentions of Haskell "platforms" and "stacks" etc. on the Haskell Wiki. But I will confess I don't really know what a "platform" or "stack" is, or which of the options will support my needs. I know close to zero about apps in the browser.

Regarding my UI needs, my app will have lots of graphics and lots of things to click on, drag, etc. It will need to be touch-screen responsive. 

Dennis