For a while I was unable to connect to my Shadow via my iPhone. While this is still an ongoing issue, a work around that allows me to access my Shadow from my iPhone is to start the app but not connect. Instead I hit the gear icon to get into the settings and scroll down and click "Display Safe Mode". This seems to allow the app to connect properly.
I am not sure what the cause of the issue is with the iOS app, but this seems to be an effective work around. Hopefully the Shadow devs can figure out the cause so using safe mode isn’t necessary.