Android 4.3 hasn't been revealed by Google yet (not officially, anyway), but apparently that hasn't stopped a version of the software for the Samsung Galaxy S 4 from making its way online. SamMobile has posted what it claims are leaked builds of Android 4.3 Jelly Bean both as a straight-up firmware for the Google Play edition Galaxy S 4 (GT-I9505G) as well as a custom ROM for the international Galaxy S 4 (GT-I9505). Digging into the leaked builds themselves, the build number is listed as JWR66N, while the build date is June 26.
In addition to the leaked software, SamMobile has posted a boatload of screenshots from the Android 4.3 builds that it's shared. There doesn't appear to be any major changes contained within, which isn't a complete shock since this is a 0.1 update that retains the Jelly Bean moniker. The new camera UI that is included with the Google Play edition Samsung Galaxy S 4 and HTC One is packed in, though, so that is one feature to look forward to.
There's no word yet on when Google will release or even announce Android 4.3. However, anyone that owns a GT-I9505 Galaxy S 4 and is feeling both impatient and brave can load this leaked Android 4.3 build onto their device. PhoneDog isn't responsible if you take the plunge and end up turning your Galaxy S 4 into a Galaxy S Brick, but if you're eager to give the unannounced software a go and know what you're doing, the option is available. For those that can't or don't want to pull the Jelly Bean trigger, I've got a couple of Android 4.3 screenshots posted in a gallery, with many more available at the links below.