iGaming Business – Bookmaker William Hill has announced a new promotional offer for fans using the William Hill Mobile Sports app to place wagers on the forthcoming National Football League (NFL) American football season. The ‘1st and $10,000’ promotion will offer more than $25,000 (€19,231) in free mobile wager credits to customers over the 17 weeks of the season. Beginning on the first full weekend of the 2013 season on September 7-8, the bookmaker will award 10 separate $1,000 free bets to active William Hill Mobile Sports customers. Five winners will be selected at random on both the Saturday and…