You can install Flash on your Nexus 7, even if Adobe doesn’t approve.
But, please note that Adobe hasn’t “certified” the Flash Player for Jelly Bean (Android 4.1) – it’s not guaranteed to work properly and you may see some bugs. Adobe is discontinuing development of Flash for Android.
Acquire the Flash APK
You can’t install Flash from Google Play, so you’ll need to acquire the Flash Player’s APK file yourself. While many websites, including the XDA Developers forum, offer this APK for download, it’s generally a bad idea to install random Android package files from the web if you can help it.
If you have an Android phone or tablet with Flash on it, you can extract the Flash APK yourself. There are a number of ways to do this, including with AirDroid. After installing AirDroid on your smartphone, launch it and log in via a browser on your computer. Click the Apps icon on the AirDroid page, search for Flash (it may be in the System section), and click the download link to extract and download the Flash APK file to your computer.
Install the Flash APK
Now you’ll need to copy the APK file to your Nexus 7 (or other Jelly Bean device). You can do this in a number of ways – by connecting your Nexus 7 via USB, by copying the APK to Google Drive or another cloud storage service, or by installing AirDroid on your Nexus 7 and copying it over Wi-Fi.
After you’ve put the APK file on your Nexus 7, you’ll need to enable the “Unknown sources” check box, which allows you to install apps from outside Google Play. To do so, go into the Settings screen. (Pull down the notification drawer and tap the Settings icon or tap the Settings icon in the app drawer.)
Tap the Security category on the Settings screen and enable the Unknown sources check box.
Now you’ll just have to locate the APK file, tap it, and install it. If you copied the APK file to your Nexus 7’s file system, you’ll need a file manager like ES File Explorer to locate and install it. If you used Google Drive, you can open up the Google Drive app and tap the APK file. (The same goes for other cloud storage services.) Agree to the installation when prompted.
Install a Browser that Supports Flash
Google Chrome for Android doesn’t support Flash, so you’ll have to use a different browser to view Flash content. Firefox Beta supports Flash on the Nexus 7, and you can easily install it from Google Play. Once it’s installed, you can launch Firefox to view Flash content on web pages. If you already have Firefox installed, you may need to quit and restart it after installing Flash.
Tips for Using Flash
If you’re only using Firefox for Flash, you may want to open Firefox’s settings screen and set Plugins to Enabled – by default, Firefox uses Tap to play for plugins.
If you still want to use Chrome most of the time, you can install Flashify to easily open pages with Flash in Firefox. When you visit a web page that needs Flash, open Chrome’s menu, tap Share, tap Flashify, and send the page to Firefox. Firefox will open and display the Flash on the page – no copying and pasting URLs required.