Apple breaks down iOS 9's features
iOS 9 is available right now to those enrolled in the iOS developer program. But the rest of us will have to wait until either the public beta in July or later this year when it’s expected to launch alongside a new iPhone.
Siri is now smarter than ever and can work out what you mean by ‘it’ or ‘this’ depending on the context. For example, if you’re talking about something with a friend in iMessages and ask Siri to "Remind me about this later today," it'll scan the open app and try to understand what "this" means.