After reading Becky Hansmeyer's post I decided to dig up some screenshots of the first version of My Opal to see just how far things have come. My Opal was released not long after iOS 7 arrived so I started off with the clean/sparse look but about 8 months later it gained a little more personality.
Radical interface changes are one way to get a users attention and not always for the better. So keep in mind that while you're progressing things there'll always be a handful of users who want to go back to the previous look and feel (made so much harder with auto update these days). Appreciate the feedback they give you but stay true to your creation and grow it the way you want to. I'll always be guided by user feedback but sometimes you need to push change through in order to end up at your ultimate goal.
I'm super proud of the progression!
Version 1.0 - 2013 - Overview Screen
Version 1.0 - 2013 - Journey History
Version 1.2 - 2014 - Overview Screen
Version 1.2 - 2014 - Journey History