When it comes to Android TV, the biggest feature is hinted in the name. TV. Or at least video in general. While Android TV does offer additional abilities like gaming, music playback and a somewhat level of browsing, there can be very little doubting that the main function of Android TV is to get your video fix, on your big screen and via an android medium. As such, the inclusion of some of the bigger video content apps like Kodi and Plex are an absolute must for some Android TV owners. That said, the latter has taken its time in becoming available on a wide scale level.
It is (and has been) no secret that Plex was making a big push for Android TV. The company announced their intention pretty much the moment Google announced Android TV was coming at last year's I/O event. This was followed in October when the Nexus Player was launched by Google and Plex, again, announcing their attention to bring their offering to Android TV via the Nexus Player. Since then though the rollout how been a little slow.
That said, before today, Plex on Android TV has been available although it was only available for those who were willing to partake with a monthly Plex allowance via their Plex Pass program. Which probably was a little disappointing for those running the app on a purely IAP basis. Well, today, all that has changed and now anyone can run Plex natively on their Android TV thanks to the widening of the availability by the company. Now, if you do own the Plex app in its free version, then you can make do with all the basic functions that are available via the free version. Likewise if you have purchased the app via the IAP option then you can utilize the premium version and you do not have to pay again. Simply, click the "Already Paid" function at the bottom right of the screen once the Plex app loads for the first time. You will be prompted to email Plex with your email address which was used to purchase the app previously. This is so they can verify your purchase. It seems you will then see the activation be switched on remotely within 24 hours. Otherwise, if you have yet to purchase the premium version then you might want to, now that the Android TV compatibility is live.
It is probably worth pointing out though, if you purchased the app via Amazon or as a free app of the day (FAOTD) then, unfortunately, you cannot use the premium version of Plex. The 'Already Paid' function on the app does state that your Amazon paid licence does not and will not extend over to the Google Play version (which inevitable is the Android TV version of the app). This is unfortunate and especially if you did actually buy via Amazon, as you will have to re-purchase the premium version for $4.99 via the Play Store.