You can not find Adobe Flash Palyer on the Google Play Store, and Chrome browser or Galaxy S4 stock browser (internet) don't support flash based websites either. So, what is the solution?
Do as follows to install Adobe Flash Player on Galaxy S4 and view flash based websites on your device, as well:
1. Download and install Firefox from Google Play (Download Firefox for Android)
2. Download and install Adobe Flash Player from Adobe website (Flash Player 11.1 for Android 4.0 (126.96.36.199))
** Go to Archived Flash Player versions to look for other Flash Player versions
** To install Flash Player on your Android device, you must enable the install from unknown sources option (Settings > Security > Mark Unknown sources).
3. Open Firefox on your Android device
4. Go to Settings and make sure to enable Plugins.
5. Now, you can view flash based websites on your Galaxy S4
Read More Galaxy S4 Tips and Tricks