Marketplace App - API Endpoint to retrieve list of portals who have app installed
Currently there is no way to check whether a specific portal has your app installed, or to get a list of all portals who have your app installed. This would be extremely useful in monitoring the users of your app. For paid apps this is almost necessary for the situation where a user uninstalls the paid app from the marketplace but their payment/subscription still exists. Another useful and related feature could be webhooks for when a user uninstalls the app. At the very least I think there should be an option to add a page redirect for when a user uninstalls the app.
