Mobile app: Game based on predicting sports outcomes

I am looking for someone to assist me build a cool new app, where:

+ Users start "leagues" (as like in fantasy football)

+ Users have an opportunity each day to predict sports outcomes for the subsequent day (e.g., who will win a baseball game, how many points Kobe Bryant can score, number of goals in a hockey game, etc.)

+ Users tally points based on number of predictions they will get right (adjusted based on level of difficulty for each prediction)

+ App automatically maintains scoreboard that compares for every users points over specified period of time

In essence, I want app that allows people to do with their friends based on ability to predict sports outcomes.

Desired Skills

Android, iPhone, iPad