To download Opera, users will be prompted to verify that they are at least 17 years old.
When it comes to rating browsers, Apple treats the entire Internet as its content and thus always gives the highest rating to browsers, as apps in the App Store demonstrate.
According to Apple's app rating system, an app with the 17+ rating “may also contain frequent and intense mature, horror, and suggestive themes; plus strong sexual content, nudity, strong language, alcohol, tobacco, and drugs which may not be suitable for children under the age of 17.”
Although Opera only commands around two percent of the browser market, software analyst Michael Muchmore said it delivers the "most innovations."
Opera recently announced pinch-to-zoom mini apps for the iPad, iPhone and Android phones.