I can see a great deal of work is going into it, and I’m sure it will be a big improvement.
That said, it appears no thought has been given to improving accessibility for those who have either vision or mobility impairments.
Just as an example, when the primary navigation is put at the very bottom of the screen, those using either Voice Over or switch control navigation have to step through everything else on the screen before reaching the navigation choices, making use of the app both cumbersome and physically tiring.
I suggest the UI team take an hour each, put on a blindfold, and try using voiceover to complete 3 or 4 set tasks. This will give them a better understanding of accessibility requirements.
Those with physical challenges are a significant market for home automation systems. It makes sense to put at least a little thought into how the app will work for them.
There are several resources that can help UI teams better understand how to design for those using alternative controls.
Any of the national organizations for the blind can help with design tips for those using screen readers.
Resources for the needs of those who can’t touch the screen easily and typically rely on “switch control” are a little less easy to find, but Tecla, the makers of one of the most popular switch control devices, are usually happy to talk to app designers about switch control guidelines, including ADA compliance. Their device works with both IOS and Android devices, so they are very familiar with both.
I would think they’d be delighted to help showcase environmental controls based on a SmartThings hub, but of course the mobile app has to be switch-friendly.