Three weeks after the last beta release, and just a few days after Apple's developer center finished receiving a massive security overhaul, iOS 7 beta 4 is now available to download. The update to Cupertino's upcoming iOS release -- the biggest since the debut of the original SDK -- is heading out over the airwaves now, with a list of fixes and improvements far too long for us to reprint here. Of course, if you're a registered developer, you can hit up the source link to check out the entire tome of changes for yourself. If you haven't gotten an alert on your handset just yet, be patient. And, please, let us know in the comments if you dig up any interesting tidbits while poking around. http://www.engadget.com/2013/07/29/ios-7-beta-4/