App Store app id (digits, e.g. `284882215`) or bundle id (e.g. `com.facebook.Facebook`). An id with the `id` prefix used in App Store links (`id284882215`) is also accepted.

Two-letter storefront code, e.g. `us`, `gb` or `jp`, case-insensitive. Prices, ratings, reviews and text are specific to it. A code Apple does not run a store for is refused. Default: `us`.

Language of the text, as `ll-cc`, e.g. `es-mx` or `ja-jp`. Changes the language of descriptions and price labels inside the storefront. Default: the storefront's own language.