I'm using the official Plex app already. Do I need their subscription?
i do not know if subscription is the only way or you can just pay for the app.Since they changed it sometime ago, when the app wasn't free at all. Now is free but is kinda limited.
I have plex server on my Minix z64 (low pow pc) , i bought the windows app since i had some money to spend from xbox live, so i can play files from my pc using the plex app.
On my smartphones, i got the app for free from amazon, they put it quite often on their free apps, i have it on the devices i use for my daughters, a tablet and a pair of smartphones, since it is technically a 'bought' app, it can play what is on my server on those devices (two smartphones and one tablet).
On my wife's smartphone and mine i have the app from Playstore which won't let me play on media on them but allows me to send to the chromecast on my tv.
I also play my media from my ps3 on another tv but instead of using the plex app (paid app) i just browse through content as a media server , and works just fine (it is not as nice as navigating with the app, but gets the job done)
Pretty much all US carriers are abandoning that model. Subsidies and contracts are things of the past.
The 6P is going to start at $500 (+/- $50). Bank on it.
i live in spain, nexus 6 was the first nexus to hit carriers, so my guess is 6P will have the same treatment, and 5x won't be supported by them. But i guess we will know in a few days.