I’ve been increasingly looking to Livebook apps for this exact use case! Just set up a single Livebook instance on your favourite hosting provider, develop your app using Kino, or PhoenixPlayground, hit “Deploy” and enjoy!
The biggest drawbacks right now are that you can’t host anything at the root path (everything is nested under ‘/apps’), you don’t get domain-based routing, and you can’t easily design the homepage without running your own fork of Liveview.
Even so, the freedom to just jump into a Livebook, code something up and deploy it in minutes, at zero additional cost is beyond cool!
Also, with Livebook teams, you can actually have separate environments eg dev/staging/prod without compromising the workflow.
As an example, I’ve set this up on https://speedrun.dev . No apps deployed right now, but you get the gist 
