With this code you can
- Start ngrok on your dev Linux machine.
- Auto-configure the URLs at the app setup on Shopify servers - which was a constant pain for me!
- Install the extension Tampermonkey on Chrome (or perhaps Greasemonkey on Firefox?) and add a user script containing the JavaScript code in file tampermonkey.js. Make sure that the @match comment matches your app's setup path at Shopify (and is postfixed by the query param subdomain).
- On your Linux dev machine run the script ngrokshopify.sh