Thanks for explaining

I use it on and off. I get annoyed that the swiping constantly gives the wrong words.

I know nothing about all this licensing stuff. Way over my head… But, is it possible that “futo” is using us to train their software, then when it’s working great, change it to a paid app?

Those worked by sound. No power was needed or generated by the remote.

From the article…

By pressing a button on the remote, you set off a spring-loaded hammer that strikes a solid aluminum rod in the device, which then rings out at an ultrasonic frequency.

I THINK I even remember, way back, random channel changes from tapping on a drinking glass or something similar… Cool tech for the time