I know there are a lot of people out there who don't spend money to play the games, but for those of us who don't mind occasionally spending some money for boosters and/or gold bars I suggest Candy Crush Friends have something similar to a lot of the other games, where you can collect tickets/tokens/scrolls etc. by beating hard levels etc. and then have the opportunity to purchase a gold bar/booster package at a reduced price. This game is a lot of fun, but it is also pretty hard and also one of the most expensive ones to play (if you do end up buying gold bars etc. -even the piggy bank is expensive - $3.99 for just 30 gold bars).
"Sometimes the smallest things take up the most room in your heart." - Winnie the Pooh