Unfortunately, no. The volume and power features of the app only work with RokuTVs, not Roku streaming players and sticks.
You are able to turn on your TV with the app most likely because you have 1-touch play enabled on the Roku device (a HDMI-CEC feature). This is simulataneously waking the Roku device up and automatically powering on TV and switching to appropriate HDMI input.
The 1-touch play is located under Settings/System/Control other Devices/1-touch play
I think the only possible solution since using a Streaming Stick would be to purchase another Roku remote (multiple remotes can be paired to same device) and keep one on each side of room. If your Roku had been a player, rather than a stick, then could also use an inexpensive universal streaming remote compatible with Roku streaming devices.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
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