Code development of a simple math game

Tools: Objective-C, CocoaPods Deployment Target: iOS 7.0, iPhone 4 and above, Portrait App Description: In this game various simple math formulas are displayed to user (e.g. 11+11=). Under the formula there should be 4 buttons with 1 correct answer and 3 randomly generated incorrect answers similiar with the correct one. User is given a certain time limit, for every correct answer he gets some extra seconds. How many seconds he gets depends on level difficulty. User goes to next level if he gives 4 corrects answers in line. On the right and left sides there should be indicators for level difficulty and time left. Work should be done as per attached mock-ups, including but not limited to: Main Parts: Introduction View, Start Menu View, Main Game View (incl. Pause pop-up and Finish pop-up) Buttons and Lables: Start, Game Center Leaderboard, Sound On/Off, Remove Ads, Start Any Level, Question, 4 Answers, Score, 2 Animations (Level Difficulty and Time Left), Pause, Restart, Go Back to Main Menu Additional Features: Admob Ads - Banner and Interstitial, Game Center Level Builder: This SOW does not include development of levels within the code, levels will be provided in separated arrays (the fromat shall be provided by coder). The whole array shall be presented as a separete class (separate module). Questions and Answers in the game will represent only lables taken from arrays, no mathematical model is required to be developed within this SOW. Inputs All required inputs will be provided upon award of the project."