Adobe Flash Player isn't in play store anymore, if it is then only in UK.
It'not supported on Jelly Bean devices but that doesn't mean that Jelly Bean 4.1+ (also JB 4.2.x and 4.3.x) couldn't run it!

Actually Flash Player works well on Jelly Bean, to use Jelly Bean you need browser with Flash Player support. Example: Stock Android browser (Not Google Chrome / Chrome Beta).


To find the latest Flash Player and to download it: 
http://helpx.adobe com /flash-player/kb/archived-flash-player-versions. html