"Today we're introducing a new look," the company wrote in a blog post. "You'll see an updated icon and app design for Instagram. Inspired by the previous app icon, the new one represents a simpler camera and the rainbow lives on in gradient form."
The app itself has also received a major redesign with a flatter black and white appearance in line with the overall look of iOS 9. Instagram says "the simpler app design puts the focus on your posts and keeps your features in the same place."
Instagram is free on the App Store for iPhone. The version 8.0 update should be rolling out worldwide for all users today. Instagram's other apps Layout, Boomerang, and Hyperlapse have also received new icons.