For those interested in the GitHub integration / preview pull request features that Netlify offers, but don't want to migrate from your current host: I'm developing a product called FeaturePeek[1] that will spin up static builds into a feature environment you can share with your team / publicly. Unlike Netlify Dev / ngrok, you don't need to be online with your feature branch checked out for others to preview it. We can run dynamic builds too, and are agnostic of your host or cloud provider because we don't focus on production deployments. On top of that, we provide some collaboration tools so you can annotate / comment directly on the build.
The `netlify dev --live` command opens up a tunnel to your local dev server port. If you close your laptop, the connection closes. Similarly, if you switch branches, the content of your build will change, even though the URL you've shared remains the same.
[1] https://featurepeek.com