It doesnt work on all smart TV's. I have a Samsung and it doesn't allow the downloading of Kodi. I think the only ones that work are those with Android driven software like LG's.
I bought a pre-loaded box from Android. Cost me £40 and i got a keyboard with it too. Took me fricken ages to work out how to use it properly, but rather than be stubborn and i went online and read some guides on installing repositories etc. I mainly use it for movies and TV series (using Exodus or SALTS). For live TV I use Modbro and few others. Pheonix occasionally has some good sports links. I used to use Wookie as the main platform but switched to TvAddons and i really like it.
Can take some time to get your head around, but once you get going its fairly simple.