Yeah I have an annual subscription to Hockey Streams as well. It was like $109 for the year or so when I subscribed. Hockey Streams will work with a number of set-top boxes/media dongles like Roku 3/the Roku stick, Apple TV and Chromecast. And it also works with tablets and smartphones. I watch Leafs hockey (and other hockey) on the Hockey Streams app on my Roku 3 with a wired Ethernet connection (for better reliability). And I watch on my Android tablet over Wi-Fi (not as reliable. Streaming Netflix is fine on my tablet. But hockey streams in HD tend to lead to more hiccups). I don't have an iPad and haven't bothered streaming to my iPhone so I don't have any personal experience with the service on Apple products.
It's odd to think how Rogers is trying to push Rogers NHL Game Centre over mobile. You'll have to use a Wi-Fi hotspot or Wi-FI at home unless you want to run up a huge data overage on your bill. Even if you were to stream in Standard Definition, I would imagine that hockey consumes a lot of data. Netflix consumes about 0.3 GB/hour on the lowest quality settings in standard definition. That's about 700 kbps video quality. I don't think Rogers NHL Game Centre has that low quality of an option. A typical hockey game could set you back 750-900 MB easy even at those settings. That's perfectly fine if you have home internet with 60+ GB bandwidth/month. But most mobile data plans max out at 6 GB. And that's only if you get a retention deal or promo. So I stick to watching over wired connection at home on my HDTV with Roku or over Wi-Fi with my tablet.
I'm not quite sure if Hockey Streams is actually legal to be honest (even though it is a paid service). They are supposed to respect local blackout laws I think. Since hockey streams is probably operating overseas, maybe they aren't subject to the same laws? Also using a VPN like Hola Unblocker to spoof a foreign IP to bypass local blackouts and access foreign content is probably illegal as well. But I still do. I don't care. I do it all the time. Netflix US has a lot of content that Netflix Canada doesn't and Hulu isn't available in Canada yet. Hulu is great. I use UnblockUS instead of Hola because it's more reliable (it's $4.99/month as opposed to free) and I can set my VPN up to my router so that I can watch Netflix US on any connected device (laptop, Roku, Android tablet, my sister's iPad. PS3. Xbox 360. I bet it works with PS4/Xbox One/Wii U/Wii too.)