This release can be downloaded even by those without a developer account and comes with a new lock screen design, some overhauled apps, and more.
http://www.notebookcheck.net/Apple-releases-first-public-beta-of-iOS-10.168719.0.html
Make sure to disable icloud backup before upgrading as if something would happen to your device you wouldn't be able to set up a new one using your back up as these are version locked!