Coin Master
Conquer the global and country leaderboards. This App has 5,000,000 downloads on Google Play with and average rating of 4.5 stars.

This Game definitely falls into the have 5 - 10 minutes to kill category. It draws on aspects found in several other games to make a fun but light game play. The basic is that you spin a three symbol slot machine to win coins and various enhancements. 

This coins are mused to build up your village few buildings and once they are maxed out you advance to the next level of themed buildings. You can also win the ability to attack, raid or protect your village,

As he game progresses you can also earn animals that once activated for a short time by feeding them will grant you special bonuses when activated. Of course different animals will grant you different abilities. 

You can earn chest by random chance or trade your coin in for different type of chest for rewards. One of the main rewards that I have experienced was the earning of cards. Once you have completed one of the many sets of cards you will be granted a bonus. The bonuses range from free spins to new pets or a combination of different pets.

You can also sign up for special offers to earn what can be significant amount of spins. Some of them that I have seen were in the excess of 1,000 spins. This higher one's are mainly for revealing personal information or signing up for special trail offers with a credit card. Something that I personally against but the option is there if you choice.

The base of the game is on earning spins which are credit to you account at the rare of 5 per hour to a maximum of 50 spins. It should be noted that if you earn bonus points you will be allowed to exceed this limit. It appears the 50 spin cap is solely for free spins earned over time.