I have the Spectrum apps on two roku sticks and on the Hisense TV. The sticks are working fine. The TV shows the Spectrum app, but when you click on it it starts to load and then goes back to the Roku screen. Normally I would try updating it, and if that didn't work, I would try deleting and reloading it; but since the Spectrum app is no longer available, that might just make it worse.
I was advised by a Spectrum installer last week that they are no longer supporting the "Spectrum App" on Roku. When I asked him why he said that Spectrum is phasing out many of the perks they once gave their customers. One thing that I found is that they no longer support the hidden receiver by using extended remote receiver. So in other words you have to have a direct line of sight to the receiver to use the remote. Pretty chincy if you ask me. They'll sacrifice those little creature comforts for the customer to make a few penny's more on the bottom line! Oh yeah if your grandfathered in to an older contract with Spectrum get ready for them to stick it to you very soon! Those with older contracts that were from say Brighthouse or Time Warner had rights under that contract that as long as "they" never change their plan they would receive almost every HD channel known to man. Now in the next 6 months they great city and national government is allowing them to negate that contract. You'll lose programing, your bill will go up, and the service you once had will diminish. The bottom line? They have us all by the short hairs! The advice given to me by a trusted installer is simple. If you can finding a streaming service that gives you what you want without all the bull**bleep** take it and use an OTA antenna to get your locals if possible.
I had a Time Warner Plan and liked it, but they kept raising the price until I dropped it. After a couple weeks I signed up for Spectrum. It was much faster and much cheaper, but I lose some TW channels I liked. Now they are starting to raise the Spectrum price. Well, 5G will replace everything.