The first public beta of iOS 9 is now available for all users registered in the program beta software from Apple. This, comes a day after the beta 3 private developers, allows users to try out all the news of the latest version of iOS before its official release planned for autumn.
To access the beta program you must first sign in with your Apple ID on beta.apple.com . If you are going to proceed with the installation of the software, which is still very stable, remember that this is a beta version. Not by chance in fact Apple recommends you install the beta versions of its software on iOS devices secondary.
You should also make a backup of your data via iTunes or iCloud before installing the beta of iOS 9. That way, if something goes wrong, you will not lose applications, photos and other media files.