iOS 10 And macOS Sierra Public Betas Are Now Available [UPDATE A Second Public Beta Has Been Released For Each OS]

Apple has opened the public beta program for iOS 10 and macOS Sierra to get more feedback on bugs and features from a larger number of users. If you're not already signed up for the public beta program, you can do so here. It should be noted that Beta means that not all advertised features are functional like in the official release current releases and  you may bugs that you'll want to report. It should also be noted that you should NEVER install beta OS versions on your primary devices. Tt's recommended that you should only install the beta software if you have secondary Macs or iOS devices for testing. 

UPDATE 7/20/16 - Apple has released the second public betas of macOS Sierra and iOS 10 to public beta testers.