iPhone Giveaway of the Day - Signum: A Simple Puzzle Game About Numbers

Add some numbers and you may become a Human Calculator.
Learn some interesting facts about the Greek letter Σ (Sigma) while playing.

Features:
• Change the difficulty between EASY and HARD or play both difficulties at the same time.
• Toggle single challenges on or off.
• Change numbers type between positive and all integer numbers.
• Reverse operation tiles (+ becomes - and the other way round).
• When in trouble just shake your device to start over.
• Game Center integration lets you view your best score and the Leaderboard!
• You have ability to listen to your own tunes in the background. Just play a song with your Apple music player and start the game.

Enjoy!