Officially Apple announced that iOS 9 would be available as a free download on September 16th. When it arrives next week, you'll be know the new features like new and improved Siri, system-level security settings and split-screen multitasking on the iPad (iPad Pro) that how it will actually works.
Native apps like Maps ,Notes and others have also had been refreshed, so if you haven't been adventurous enough to test-drive the public beta, there will be a lots of new stuff for you to try. And there's that brand-new "News" app too, serving up personalized content to your devices for reading on the go.
To turn your picture into video, newfangled "Live Photos" is there. iCloud pricing has been revised to 50GB for 99 cents a month, 200GB for $3/month and 1TB for a $10 monthly fee.
If your plan is to move from Android, Apple's new "Move to iOS" app will arrive alongside iOS 9 as well to lend a hand moving your stuff over to a new phone/tablet. In terms of compatible devices, the new OS will play nice with iPhone 4s and later, 5th gen iPod Touch and later, iPad 2 and later and iPad Mini and later when it arrives in just a few days.
Original Sources: Engadget