Implement Page View Detection for App/Web Content Differentiation

"Have some way - e.g. a shortcode or some kind of setting on blocks/pages - that allow us to check if a page is being viewed via the app or whether it's being viewed by a web browser. That would allow us to set our pages so that they show different content to app viewers vs web browsers - for example promotions for paid products can direct to the in-app purchase page in the app