A better design for the mobile-app

I need a design for a tecnical finished eBook-Reader app. That means the layout is done, but the colors and shapes of the elements are horrible. a new app-icon would be also cool.

I have Screenshots of every screen, fonts and icons, a working demo-app, and of course demo-files.

About the Project: Its an open-source project for a new file-format specially for manga and comic ebooks. The app itselve ist NOT open source, but free to use without adds or collectig data, coz I couldn’t find a license which forbids comercial usage