The first mobile game that officially overcame the bar of one billion dollars earned was a card butler with elements of Match-3 – Puzzle & Dragons.
This was recently reported by the Japanese gaming concern GungHo, who noted that Puzzle & Dragons accounted for 91% of the company’s total revenue in 2013. GungHo’s sales for the whole of last year amounted to $1.5 billion. Most of them – $775 million – were received from Google Play.
Source: http://www.pocketgamer.biz