Wow. Out of the blue, an Android 4.3 rom hits the internet, and it's not built for the Nexus 4, or 7 or 10, but for the Samsung Galaxy S4. What a strange turn of events.
Of course, I couldn't stop myself from diving right in, and while I don't have a Galaxy S4 to show you screenshots, that's really not a big deal, because this leak pretty much looks identically to 4.2. If this build of 4.3 is near completion, it looks like we're getting a pretty minor update. But hey, 4.3 is 4.3. It's worth a look no matter how minor it is.
4.3 is API version 18 and still called "Jelly Bean." This build, for some reason, has the region in build.prop set to South Africa and the language set to Afrikaans.
Just where the heck did this come from?
The craziest thing about this 4.3 leak is the new Wi-Fi power settings, where what we think of as "off" isn't really "off" anymore.
<string name="wifi_scan_always_available_summary">"Let Google's location service and other apps scan for networks, even when Wi-Fi is off"</string>
<string name="wifi_scan_notify_text_location_on">"To improve location accuracy and for other purposes, Google and other apps may scan for nearby networks, even when Wi-Fi is off. If you don't want this to happen, go to Advanced > Scanning always available."</string>
<string name="wifi_scan_notify_text_location_off">"Apps may scan for nearby networks, even when Wi-Fi is off. If you don't want this to happen, go to Advanced > Scanning always available."</string>
<string name="wifi_scan_always_turnon_message">"To improve location accuracy and for other purposes, %1$s wants to turn on network scanning, even when Wi-Fi is off. Allow this for all apps that want to scan?"</string>
Google wants you to leave your Wi-Fi on, or at least partially on, all the time. Now I know you might immediately scream "MY BATTERY LIFES!!11" but this will probably save battery. Google wants you to leave Wi-Fi on so that apps can get your location, but consider that the other option for location is firing up the GPS chip, which is a battery's worst enemy.
The important thing to keep in mind is this if you hate this, you can turn it off. The option is just buried under an "advanced" menu. Turning off "Scanning always available" will make "off" for Wi-Fi really be "off."
Some of this wording is rather interesting: "To improve location accuracy and for other purposes." Those "other purposes" probably (that means this is the speculation part) involves shipping that Wi-Fi location data back to Google, which is how the Wi-Fi location service currently functions. The only way to use Wi-Fi hotspots for location data is to build a map of SSID (hotspot name) locations. You do that by running around with a GPS and Wi-Fi chip and virtually stick Wi-Fi pins on a map. I have a feeling we'll now all be updating those Wi-Fi maps for Google, silently, in the background (unless you hit that checkbox). Hopefully they've found a way to do this without killing the battery. I suspect they have.
There really isn't much left to cover in this leak. I'm not going to be able to see any kind of performance improvements in a teardown, so I really have no idea if there's been work there. We know all about the new Camera app, which shipped with the Google Play Edition Devices. Bluetooth LE is included, but we've known about that forever. The Roboto fonts have gotten a tweaking, which Liam expertly covered here. There's one or two new development options, and some other tidbits, but that's about it. Those of us hoping for updates to the clock, Quick Settings, Contacts, Dialer, or any of the other built in apps are out of luck. Nothing says this is a complete build of 4.3, though, so we really have no idea how close this will be to the final version. We'll just have to keep waiting.