A number of web articles and people have said how good Kodi is so I thought I would investigate.
Kodi runs on RPI, android phones, linux, Windows, firestick as well as dedicated platforms. Initially I have tried it out on RPI in two flavours: (1) installed as a package on Raspbian and (2) as part of a dedicated Libreelec installation.
When you start up either option the Kodi screen is displayed on the RPI console (ie attached HDMI screen). Kodi can play local music or films. There is also a youtube addon which comes as part of the existing kodi repository. I tried all of these but they are not as convenient as the same functions under windows so not of much interest.
If you connect a TV to the RPI HDMI connection you see the Kodi screen as expected. Thanks to a feature called HDMI-CEC you can use your remote control to navigate the Kodi menus: up, down, left, right, select, return, exit etc. The TV sends signals back down the HDMI cable to Kodi on RPI which responds accordingly. The kodi interface is most suitable for a remote control rather than mouse and keyboard so this makes using kodi much more convenient - although a keyboard is much easier if you are typing URLs etc.
I did try a number of add-ons...
Covenant
A well-known add-on for watching movies and TV shows. It is now available from http://archive.org/download/repository.xvbmc. It looks like most recent movies are available and the links for a few popular ones appear to work. Links for TV programs didn't work for me, they are either out of date or there are too few sources. You generally wait for a couple of minutes before you find out whether a movie is available or not. In practice torrent downloads would be more convenient. I found the "most popular" listings interesting to decide on something to watch - although I might watch from a different source.
PureVPN
I chose PureVPN as a commonly-used well-priced VPN service with lots of locations and with good, specific installation instructions for Libreelec/Krypton/RPI. It also works on lots of other platforms including Windows and it has a plug-in for chrome. For Kodi you simply download a zip file, copy it to the RPI and install the zip file. You can then choose a country location for VPN or leave it disconnected if you want.
It is a bit hard to tell what difference it makes without experimenting with it on/off but initially it helped to watch TV programs when it was set to a US location.
Simple IPTV client
Loads of IPTV channels are available by googling the internet.They are intended to be played either with VLC or Kodi etc. Mostly I found they didn't work properly or were dull or foreign. You use a .M3U file which contains details of each channel. You can load this as a URL or a file into VLC or copy the file across to Kodi which will then load the channels. In my search, I just found a few US country music channels to watch. I found the quickest way to experiment was to download then cutdown the channel list on windows, copy it to kodi using mobaxterm, renaming it as list.m3u. Simple IPTV client specified list.m3u as the local channel list so I just rebooted Kodi once I had loaded the list. It was much easier to try out channels in VLC. Unfortunately commercial ones tend to be very jumpy.
Other avenues
Many people use Kodi to watch sport but since it adversely impacts premium sports channels suitable mechanisms are regularly closed down.
Repositories are full of add-ons, some must be useful for other purposes but it is difficult to know where to start.