A closed platform is just a hurdle to overcome - but yeah, someone has to do it. If they make it a little more consumer friendly this could be very impactful.
Software wise, the couple things I'd want are music control, TOTP codes, and health data going to Apple Health instead of Mi Fit. You can get them for $60 on GearBest though, so all things considered that's a pretty good deal for what it is.