Dashboard #UI another very modern, sleek, and (dare I say) futuristic dashboard design example. Perhaps much of this can be leveraged for the app's design.
Dribbble - fullsize.png by Tony Mack
20+ Awesome Dashboard Designs That Will Inspire You
Work - UI
UI/UX on Behance
A prototype I made a while back when I was working on Dropbox Photos. More details about that project here
UI Design) Item - Ani Gif
Showcase and discover creative work on the world's leading online platform for creative industries.
Graphic design: Mobile Apps
Network App – MaterialUp
Great Mobile UI