You may remember last month when Adobe announced that Jelly Bean was not going to get Flash. Ice Cream Sandwich was going to be the last version of Android to have official support for Flash and the software was only going to be up on Google Play until August 15. It will be gone forever after that.
Some people did not like that ultimatum so they went about getting Flash to run on Jelly Bean. Even if Adobe wasn't going to provide support, the intrepid folks over at XDA were going to put Flash on Jelly Bean one way or the other.
Stempox over at the XDA forums created a guide for installing Flash on Android 4.1 devices. Censura_Umbra created a similar guide for installing Flash on the Nexus 7. The guides detail how to install Flash Player on Jelly Bean devices that will work just like Flash has always worked before.
For regular Jelly Bean devices, you're going to want to download the .apk of Flash Player. After that, copy the files to the SD card of your Android device. Install it using a file manager and start up the browser. In the browser, uncheck the Flash Player option and you will now have the latest version of Flash installed on Jelly Bean.
As for Nexus 7 users, you're going to want to root the tablet first. After that, download this browser to the tablet. Place the app in your /system/app folder and change the permissions from rw----- to rw-r--r--. If you see a file named browser provider.apk or browser provider.odex, you will need to add a 1 to the end of the file name. From then on, you should have Flash installed on your Nexus 7.
Stempox notes that Flash is not officially supported on Android 4.1, so there might be some compatibility issues. He does say that it works just fine for now. There might be other issues that arise over the next few months, but other developers will find workarounds. With the Android platform being as open as it is, it's nice to see developers keeping software alive on devices.[h/t: Talk Android]