There are some minor changes to iOS 11 including new Camera and Settings icons, updates to the Music Control Center widget, the temporary removal of iCloud Messaging, restored pre-iOS 11 favorites in Health, and more.
If you're interested in trying out the preview software, you can join Apple's Beta Software Program.
Help make the next releases of iOS, macOS, and tvOS our best yet. As a member of the Apple Beta Software Program, you can take part in shaping Apple software by test-driving pre-release versions and letting us know what you think.
You can join the program at the link below. Remember, it's strongly advised that you don't install beta software on a primary device as a bug could cause loss of data or functionality.