It's nice to have loading even for a second, since it's on design templates, can use a timer for example before switching, but don't put delay in data layer
app should tell user if where is no data or if error occurred, toast looks bad on watch devices so try to work around it
loading screen should be animated, can use custom view for this
same as for other screen look for design to look similar
here, i put screen from design template. sizing a bit off