In addition to the above updates, the biggest highlight of iOS9Beta3 is the introduction of a newly transformed two-factor authentication system. The new two-factor authentication system is different from the current two-step authentication system, which needs to use "different ways" to trust devices and provide authentication codes.
Because I just opened the download, there are not many users who have experienced it, and there are fewer bug feedbacks. However, given that there are many problems in iOS9Beta2, iOS9Beta3 version has fixed the inherent bugs, so it is still worth upgrading.