Roku users can get the app through Roku's Channel Store and subscribe to Apple TV channels directly on Roku devices.
Users of Roku will be able to access Apple TV+, the pipeline containing Apple's original video content, when it begins operation Nov. 1.
Shares of Roku, Los Gatos, Calif., finished at $132.82, up nearly 12%. The stock has more than doubled over the past year.
Not everyone is enamored with Roku. Skeptics point out that the company faces intense competition in the market for devices that include multiple subscriptions.
After that news, Loop Capital analyst Alan Gould offered a bearish take on Roku to Reuters.
"We are having a tough time justifying Roku's valuation, especially facing such substantial competitors as Amazon (AMZN - Get Report) , Apple and Google (GOOGL - Get Report) ," he said. "Now you can add Comcast."
Shares of Roku closed that day -- Sept. 18 -- at $129.88. Gould has a sell rating on the stock.