If I have to buy an Apple TV for some things, an XBox One for others and an Amazon TV (if they ever release it) for Unnamed New Top Gear Show I'm just gonna give up and use my extra time to learn Haskell.
(I did try IPTV, but my downstream speed is 8 megabit on a good day and it wasn't enough).
Your post is otherwise good; however its worth mentioning that the services tend to be narrow but extremely deep.
This will have interesting market fragmentation effects... Theoretically I could change the channels tonight between full metal alchemist reruns and ESPN, although not being interested in sports, I won't. But I could, and if I was really bored maybe I'd magically transmute into a rabid rugby fan. In an era where credit cards have to be whipped out and customer service argued with to change the channel-app, its likely I'll subscribe to an anime streaming service and never even have the ability to see ESPN.
And the follow on to that, is as a long term survival strategy, "TV apps" will almost need to let people stream one show per week for free with no subscription, otherwise due to normal churn you'll get 5% of your subs leaving annually and 0% new subs. At least currently, middlemen publishers need a smooth on ramp to survive.
And the follow on to the follow on, is people who only watch one show on XYZ network will likely watch for free, and the "TV app" ecosystem will likely smell a lot like the existing premium channel marketplace.
And the follow on to the follow on to the ..., is existing premium channels need to watch out... if the history channel gave up hitler, truckers, pawn shops, fishermen, and all the other stereotypical reality TV shows and actually did history for a change, HBO better look out if they think they can do everything with a headliner of a medieval g0repr0n series, surely a dedicated premium history app-channel could blow them out of the water, in fact trying to do everything will get them blown out of the water for everything, and given the lack of subscriber interest overlap, they're likely utterly doomed.
crunchyroll.com
I use it on my PS4 (I think they have a Wii-U app as well).
I think the idea of television as a big dumb screen driven by something else has a lot of merit, but I doubt it'll be run by a smartphone.
The thing that really struck me about Popcorn Time wasn't the fact that it was "OMG piracy!" or anything groundbreaking (torrents aren't new and some clients feature watching while you download). It was the fact that I could skim through every show, bookmark favorites, and see which episodes I already watched. You could search by genre or popularity or year like on Netflix. And there were no issues of trying to figure out which service has the show I want to watch, which one has the site that only works properly in that one browser, etc.
My takeaway, as someone who constantly flirts with cord-cutting, is that I'd totally pay someone (even Comcast) for a legal service like that. Hell, I'd even pay $50/mo or whatever cable costs on top of my internet service. In fact, I might even pay more because I could skip some of the other subscriptions. In fact, if cable is feeling the crunch from Netflix, then maybe they ought to out-Netflix Netflix.
I already treat Netflix like a low-cost equivalent to basic cable where you can't just go in expecting to find a certain new movie or show but you can usually flip around and find something you'd like to watch. I understand why it would be tough for some companies to negotiate the contracts for all that content but if anything, cable companies have loads of experience and existing partnerships for this sort of thing.
TL;DR: I'd gladly pay $50/mo for a legal Popcorn Time that delivers current and previous seasons of lots of shows in an easily searchable and bookmark-able interface via on-demand streaming. Streaming shows/series isn't new anymore but the missing piece is consistency and a single interface. I'm sure they'd screw it up in reality but if I'm fantasizing about the "perfect TV" that I'd gladly pay for, that would be it.
I should add that you shouldn't expect to save much money from this, you'll likely end up spending the same or more trying to recreate everything you watch (the savings will only be to someone who watches a very small amount of content). The economics of bundling are almost impossible to beat. The difference will be improvements in user experience and enabling new experiences entirely (see the QVC app).
This isn't necessarily bad for cable either, their content acquisition costs will go down and the ISP business will only grow.