Sorry there is no Firefox available for that platform. Panasonic Viera Connect Apps Marketplace is a "closed garden" - you can only "install" what is available from that Marketplace. Those apps are run from the Marketplace "cloud", they aren't installed on each individual device as is done with desktop / laptop devices. As with most other mobile devices like smart phones and tablets, plugins like Flash aren't permitted or needed. HTML5 is used to play video / audio files.