Sony and samsung use the Below links: will update soon with some more easier way to install the app.

http://www.sony.co.in/bravia-lcd-tv/feature/Sony-Entertainment-Network/498174#/operatv

http://www.samsung.com/uk/support/skp/faq/1052455


AMAZON FIRE TV
http://www.amazon.com/gp/help/customer/display.html?nodeId=201452870