Last Updated: November 13th, 2012
If you want to update your Nexus 7 to official Android 4.1.2 that started rolling out earlier today but your turn hasn't come yet, you have two options: wait (possibly for a while) or flash it manually. The latter is absolutely safe and lets you bypass the line without any risk whatsoever. Even better - you don't even need to be rooted or running a custom recovery - updating with Jelly Bean and full stock recovery is easier than ever before.
Let's get to it.
Prerequisite: Your Nexus 7 should be running Android 4.1.1 build JRO03D.
Download the JZO54K Android 4.1.2 update zip from Google's servers (32,862,193 bytes, MD5: 1a68f499129ae2ee373806a9cad13174).
Last Updated: August 23rd, 2012
Update: Google has removed Modaco's app from the Play Store. Boo, hiss.
So Adobe's Flash for Android has gone the way of the dodo, and it can no longer be downloaded from Google Play. Many users have already made sure to keep a backup of the APK handy for the odd occasion when a video is still only available in Flash form (I'm looking at you, Zero Punctuation). But what id you lose your device, or accidentally wipe your SD card, or forget how Dropbox works? Thankfully ROM developer and modder extraordinaire Paul "Modaco" O'Brien has made a work-around and posted it to the Play Store.