This app was mentioned in 5 comments, with an average of 1.20 upvotes
These are some of the apps I've been using: TVCast, Server Cast, Web Video Cast, I'm sure there are more but these are simple enough for me. There is no way to get a TV guide or even channel list on the Roku, but these apps will allow you to cast the stream to it, and I don't think it's actually a "cast" like a Chromecast, I can turn off my phone/tablet and the stream keeps playing on the Roku (stream stick in my case), I think it just gives the Roku the link. Also, the streams have to be in m3u8, ts don't seem to work. The TVCast app also accepts an EPG link so you can see EPG on there if you want, the other 2 only handle the stream links, no EPG.
TVCast, Server Cast, Web Video Cast, probably more, all working methods to watch IPTV with a Roku. Server Cast is the easiest, no extra features besides passing the stream links to the Roku, no apps needed on the Roku as it just uses the built in stuff. TVCast is the most IPTV purpose built app but EPG is hit or miss, needs the companion TVCast channel on the Roku. Web Video Cast has a lot of bells and whistles, unnecessary if you're just looking at getting IPTV on the Roku, also needs it's companion channel Web Video Cast.
With all of these, they don't give you any real IPTV cable like experience on the Roku itself, they all just send the Roku the links. From my experience the device you use to "cast" doesn't actually need to be on, just seems to be used as the link handler.
As long as you have an m3u file you can load up on a phone or tablet ,you can cast to the Roku, doesn't matter the service. Mileage may vary of course.
The way I'm currently doing it is with a cast app, specifically:
https://play.google.com/store/apps/details?id=com.gfuentesdev.myiptvcast
And you're probably thinking you don't want a device that has to do the casting, well on the Roku Sticks I'm casting to it seems to just receive the link as the "casting" device doesn't seem to need to be turned on after it's sent link to the Roku.
If you don't care about EPG on the app, maybe because you wouldn't see it on the Roku anyways, then you can also use one of these that only do casting:
https://play.google.com/store/apps/details?id=com.instantbits.cast.dcast
or
https://play.google.com/store/apps/details?id=com.instantbits.cast.webvideo
They both seem exactly the same to me, both work just as well.
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Well, I think a Chromecast would work by the sound of it but I keep hearing it's underpowered, slow to load. I already had the Roku's so I didn't have to search there.
The app I use on Android tablet is TVCast: https://play.google.com/store/apps/details?id=com.gfuentesdev.myiptvcast and there is a app for the Roku to match. The advantage to TVCast is that it's meant for IPTV, so you get the channel names and EPG on the tablet. The TVCast app on the tablet CAN play the channels on the tablet, but when used with the Roku the tablet is basically used as a remote, nothing plays on the tablet, just your list of channels visible. And it is supposed to be compatible with the Amazon Fire TV (not sure if that includes the Fire Sticks), Chromecast, Roku, Apple TV.
There is also this Web Video Cast: https://play.google.com/store/apps/details?id=com.instantbits.cast.webvideo that will also work (and works without any extra apps on the Roku) but if you don't give it an m3u list then it just loads a long list of links with no information such as channel name and no option for EPG but if you download the m3u in an editor and give it that it will atleast show the channel names.
Here is the link for Android: https://play.google.com/store/apps/details?id=com.gfuentesdev.myiptvcast