I just finished V1 of https://wd.gt/ and was thinking of doing a ShowHN today. Basically it's RSS for widgets. You define some json and host it and then you have a dynamic, web-powered widget with no additional app required besides a generic viewer. Rendering these images would be a perfect fit for widget.json.
https://apps.apple.com/app/id6444323235
Edit: Posted a ShowHN here with more details https://news.ycombinator.com/item?id=33777705