I used the app breifly when setting mine up before deleting it. The 2 things I used it for was updating the firmware and remapping the voice control button to instead change the noise canceling amount.
The app doesn't do anything in Color Soundlink models that you can't do with the buttons. I couldn't even set the bass/treble so I erased it. It's quite useless.
It hasn’t been useful for the past 2-years since they’ve stopped making firmware updates for that device.