I feel like the implementation was a bit gimmicky. I first used an IR transceiver as a remote on a late-model palm and the interface was much better than most apps I found on Android.
I wonder if it would be possible to pack that functionality into a smart-watch
You can do something similar with the knock/tap feature. I have mine set to activate assistant and drumming a finger on the back twice about 1" below the camera works pretty consistently