Google's Siri-alternative is indeed coming to Apple's iOS. At Google I/O, the search giant confirmed that Google Assistant will debut on iPhone as a separate app. With Assistant on iOS, Google is basically competing with latter's Siri and expanding Assistant from Android and Google Home to competing platforms.
Google Assistant won't be able to take full advantage of the iOS ecosystem like its counterpart. While Siri is baked into the root level of iOS, Google Assistant only gets app-level permissions. The Assistant will be able to do things like send iMessages or play songs from music streaming platforms. However, it won't be able to set an alarm or be trigger it by saying the phrase "Ok Google"
Google Assistant was announced at I/O last year as a conversational digital assistant. Google says the Assistant is already installed on over 100 million devices and also works on Android TVs. It could also make its debut on home appliances later this year.
Google Assistant currently supports only English, but Google is planning to add support for French, German, Portuguese and Japanese soon. The Assistant is now available for download from the App Store in the US and will soon become available in other countries as well.