There's a Kodi thread here, but flagging this as it could be useful for a lot of folks too
https://emby.media/Emby's a client / server app that's similar to Plex, but offers much closer integration with Kodi
(comparison between the 3 here -
http://cordcutting.com/plex-vs-emby/)
Been using this for a while now, and been quite happy with it. For those using only one Kodi client / player, this might not be as useful, but for those that are managing an increasingly growing media collection, and have multiple clients as well (i.e. media players in multiple rooms at home), this could tie everything together nicely
What it does is to let the Emby server app manage your library (including identifying all your media, downloading images and subtitles) and stream these to Emby clients
Easy enough to use a regular web browser to act as your Emby client, but there are ready-built clients for Samsung TV, PS4, Xbox One, Roku, Chromecast, Nvidia Shield, among others. But it's the integration with Kodi that stands out (via a Kodi addon), making it transparent, as the addon automatically populates your Kodi library
You do need a machine (preferably a NAS, or a low-power PC) that's on 24/7 (or at least when you want to stream your media) that will host the Emby server. If your internet connection at home is fast enough, you can actually stream externally as well
I've never used Plex, but it does look like Plex is simpler to install and set up. Emby's a bit more complicated, but once you have it running, you forget it's even there (since you're using Kodi as the front-end)
My real world use -
Automated/scheduled downloads managed by Sonarr (for tv shows) and CouchPotato (for film) - sent to Emby server to manage
Multiple internal and external Kodi clients accessing the Emby server
Have about 8 accounts set up (for friends and family), with each account able to have their own history and watched status
Using a QNAP 653A to host the server apps, and I've seen it stream to 4-5 clients concurrently with no real issues. Rather than use Exodus (where sources could be hit and miss), friends/family just stream from me directly
Happy to walk folks through the set up as best I can