Currently I'm focusing on the desktop web app, using Vue.js. A responsive mobile view will come later. The "wizard" for creating short URLs (screenshot below) is nearly completed, it's the Analytics Dashboard that will require the most love.
I'm working on the server, too, using Go. It will be deployed on a Compute Engine by Google. Right now it uses BadgerDB to store basic information about each short URL, but all analytics for click throughs are provided to Google Analytics. There is a limit to API calls but since this is a toy app it won't be a problem (or at least it'd be a good problem to have).