Take a look at existing app from fono and ringo.
Recents, National, International contacts screen can be merged.
Account screen has access to multiple services like the funds screen on boss revolution. We will be introducing mobile topups, Incoming numbers (like onoff app), and mobile credit transfer like sendly.com app.
What to avoid
Design should accomodate all mobile devices. preferrably universal for iphone and android. The winning designer will work on additional screens and in supporting future versions of the app.