If you have a custom Discourse app or maybe an app for your company, you might want to show a custom app banner to your users. Discourse only has the ability to refer people to the Discourse app using the Other ->
native app install banner site setting, like this one:
The discourse-custom-app-banner allows you to configure your own iTunes / Android apps and show a banner for those instead.
The plugin can be found at GitHub - discoursehosting/discourse-custom-app-banner