Our app EZ Exporter may be able to help with this. It won’t be a “live” feed, however. The most frequent automated export schedule we support is every 15 minutes.
A potential setup is something like this:
Use EZ Exporter to schedule a CSV export every 15 minutes to Dropbox (or Google Drive, Google Sheets), overwriting the existing file in Dropbox with the latest Shopify data.
Create a public view-only “shared link” of this file which you can then share with your customers.
So as EZ Exporter overwrites that file in Dropbox with the latest data, that “shared link” the customer is viewing also gets updated to display the latest data.
Please note that depending on the amount of products/variants in your store and fields you’re including, it may take longer than 15 minutes to generate the report (e.g. if you’re including metafields data, this slows down the export as it requires additional API calls). We support the following export schedules: every 15 minutes, every 30 minutes, hourly, daily, weekly, monthly.
Please feel free to reach out to us if you have any questions about this.