It appears that simply having Spotify on the phone causes the Pixel Stand app to crash. Took me a while to figure why the Pixel Stand app kept crashing out but the tl:dr story is this: When I uninstall Spotify the Pixel Stand app works properly. When I reinstall Spotify - and without even opening the reinstalled Spotify app! - the Pixel Stand app crashes, giving a "Pixel Stand keeps stopping" error message. Anyone else have this problem?