15. The Sims FreePlay
Estimated daily revenue: $68,213
What it is: The Sims FreePlay lets you create up to 32 characters, design homes, and play out your Sims' lives. When you complete certain goals you earn lifestyle points that you can spend on fun items.
How it makes money: If you don't want to earn those lifestyle points through game play, you can purchase the currency, along with Simoleons and Social Points. These can be used to buy objects and skills.
Who makes it: Electronic Arts has been around since 1982 and has 9,000 employees around the world. Some if its more popular games are The Sims, Madden NFL, FIFA Soccer, Need for Speed, Battlefield, and Mass Effect.
Top in-app purchase: $19.99 for a carload of life points
Estimated daily new users: 18,429
14. myVEGAS Slots
Estimated daily revenue: $71,921
What it is: myVEGAS Slots is a virtual slot machine that lets users win real rewards from resort and entertainment partners, including Bellagio, ARIA, MGM Grand, Cirque du Soleil, and Wolfgang Puck.
How it makes money: It makes money like a real casino by charging for chips.
Who makes it: PlayStudios was founded in 2011 and employs 64 people. According to the company, there are 56 million people playing its mobile and web games.
Top in-app purchase: $99.99 for slots jackpot chips
Estimated daily new users: 17,844
13. Marvel War of Heroes
Estimated daily revenue: $75,777
What it is: Marvel War of Heroes is the official mobile card battle game from the Marvel Universe, featuring Spider-Man, Hulk, Iron Man, and other characters.
How it makes money: Impatient users of this highly addicting game spend money to refill their character energy meters, which deplete when a character is used and refill only slowly on their own.
Who makes it: Mobage published the game along with Marvel Entertainment and Cygagames, the creators of popular app Rage of Bahamut. Mobage is a gaming network and one of the biggest mobile publishers.
Top in-app purchase: $99.99 for a crate of 11,000 gold
Estimated daily new users: 500
12. The Hobbit: Kingdoms of Middle-earth
Estimated daily revenue: $79,758
What it is: The Hobbit: Kingdoms of Middle-earth lets Lord of the Rings fans create their own Middle-earth kingdom. Users are dropped into the feud between elves and dwarves while challenged to fight off the goblins. The app is featured in one spot on the iTunes home page and has an average rating of 4.2 stars.
How it makes money: Users can spend real money to get more Mithril currency.The items you can buy with Mithril are also randomly given out once a day from Gollum's Riddle, but users can save time by buying more Mithril whenever they want.
Who makes it: Kabam was valued at $700 million last summer and is well known for games like Kingdoms of Camelot and The Fast & Furious 6: The Game. The company earned $360 million in revenue last year and has 800 employees worldwide. Its games are played in more than 100 countries.
Top in-app purchase: $99.99 for 1,600 Mithril
Estimated daily new users: 500
11. Weed Firm
Estimated daily revenue: $83,832
What it is: Weed Firm follows an expelled botany sophomore Ted Growing as he grows cannabis. Inspired by the popular show "Breaking Bad," it and includes cops, gangsters, dancers, and a variety of weed types. The game currently has an average rating of 4.7 stars.
How it makes money: You can buy items like "alien pot," "watering can," and "booster" to help grow digital weed.
Who makes it: Manitoba Games hasn't released any other apps besides for Weed Firm, which launched on May 5. While the app is fairly controversial, the developers include a disclaimer: "The creators of this game do not encourage the cultivation or use of cannabis. The plot of this game is solely a work of fiction and should be viewed only as such."
Top in-app purchase: $9.99 for $100,000 in-game cash
Estimated daily new users: 142,224
10. Slotomania
Estimated daily revenue: $96,285
What it is: Slotomania is a social video slots game with more than 55 different games. You can send free gifts to friends and access special promotions and bonuses.
How it makes money: Just like in a real casino, the coins cost real money. And just like in a real casino, you can get easily sucked in.
Who makes it: Playtika was founded in 2010 and acquired by Caesars Interactive Entertainment in 2011. According to Playtika, its games are played by more than 5 million people every day in 190 countries, 12 languages, and more that 10 platforms.
Top in-app purchase: $19.99 for 52,500 coins
Estimated daily new users: 13,033
9. Brave Frontier
Estimated daily revenue: $108,939
What it is: Brave Frontier lets you become a superhero and save the Grand Gaia from corruption. It won the reader's choice for the Made In Singapore category in The Straits Times Digital Life Awards 2014.
How it makes money: You can buy resources to be even more powerful. Users may get hooked into shelling out money since they are developing characters and delving into a long-term story.
Who makes it: Gumi is a Tokyo-based company that focuses on entertainment and specifically social games for smartphones.
Top in-app purchase: $64.99 for a gem pack of 100
Estimated daily new users: 12,188
8. Hay Day
Estimated daily revenue: $127,053
What it is: Hay Day lets you see what it's like to be a farmer. You have to work the land and rear chickens. It seems like a lot of people are interested in virtually living the rural life.
How it makes money: You can buy stuff to make your farm even better and get yourself out of agricultural jams.
Who makes it: Supercell, which also makes several other hit games, has worked its way to a $3 billion value, with its cofounders realizing the important shift in gaming from consoles to phones. The Finnish company is giving Rovio a run for its money with its freemium model games.
Top in-app purchase: $39.99 for a chest of diamonds
Estimated daily new users: 16,673
7. Boom Beach
Estimated daily revenue: $150,629
What it is: Like its predecessor Clash of Clans, Boom Beach integrates strategy and tactical action in battle. You have to fortify your island, manage its economy, and conquer enemies' islands.
How it makes money: You can purchase in-app goods to rush big projects and help you win. This becomes more tempting when you run out of resources and can't build anything.
Who makes it: Another hit game from Supercell, helping the Finnish company achieve a $3 billion valuation.
Top in-app purchase: $99.99 for a crate of diamonds
Estimated daily new users: 18,620
6. Big Fish Casino
Estimated daily revenue: $179,667
What it is: Big Fish Casino lets users play games like Slots, Blackjack, Texas Hold'em Poker, Craps, and Roulette.
How it makes money: The app eggs you on with free coins, but eventually you'll need to put in real money to play.
Who makes it: Big Fish Games was founded in 2002 and creates games for PCs and mobile devices. Big Fish Casino is just one of its more than 300 mobile games.
Top in-app purchase: $99.99 for Sapphire
Estimated daily new users: 14,399
5. Pet Rescue Saga
Estimated daily revenue: $214,165
What it is: From the makers of Candy Crush comes Pet Rescue Saga in which you simply match blocks of the same color to save the pets from the Pet Snatchers. The challenge comes from the limited number of moves you can take to get you through the level.
How it makes money: You can buy things like extra moves and lives. Some think that Pet Rescue Saga is King's most creative and trickiest game to date, which may be why users are clamoring to spend real money on the game.
Who makes it: King Digital Entertainment went public after the runaway success of Candy Crush. After a rough IPO, however, it is trying to prove it is more than a flash in the pan.
Top in-app purchase: $2.99 for a column blaster
Estimated daily new users: 17,714
4. Farm Heroes Saga
Estimated daily revenue: $271,378
What it is: This fruit-filled adventure is another hit from the makers of Candy Crush, maybe for the healthier sweet tooth. The goal in Farm Heroes Saga is to match "cropsies" like strawberries and carrots to drive away Rancid the Racoon.
How it makes money: You can buy things like extra moves, lives, and gold bars. This comes in handy when you just can't wait 30 minutes for another life.
Who makes it: Another hit game from King Digital Entertainment.
Top in-app purchase: $109.99 for a XL gold bars package
Estimated daily new users: 24,637
3. Game of War - Fire Age
Estimated daily revenue: $572,498
What it is: In Game of War, users can build an empire, train a hero, and engage in battle to become king. The app is featured in 23 places on the iTunes home page.
How it makes money: You can purchase gold to strengthen your empire. The app is known to trigger a strong sense of community and self-importance and may convince users that more gold will help them succeed and impress others.
Who makes it: Backed by Y Combinator and Menlo Ventures, Machine Zone has been aiming to create a scalable social gaming experience. Since launching in July 2013, Game of War has consistently ranked in the top five highest-grossing apps for iOS.
Top in-app purchase: $99.99 for 28,000 gold
Estimated daily new users: 18,949
2. Candy Crush Saga
Estimated daily revenue: $884,676
What it is: In Candy Crush, you have to work your way through levels of brightly-colored candy-filled puzzles, and you can compete with friends to get the highest score.
How it makes money: This game is incredibly addicting. Just ask our reporter Megan Dickey who spent $127 on Candy Crush in one week. While free to play, the game lets you can buy extra moves or lives to feed your addiction.
Who makes it: This is King Digital Entertainment's breakthrough hit.
Top in-app purchase: $1.99 for a Lollipop Hammer
Estimated daily new users: 34,119
1. Clash of Clans
Estimated daily revenue: $1,118,457
What it is: Clash of Clans is a combat strategy game that lets you build a village, train troops, and battle with other users. It is featured in two places on the iTunes home page and has an average rating of 4.6 stars.
How it makes money: Users can buy in-game items like gems to help them take over the Realm by expediting the construction process. Users get more gems automatically after a while, but impatient users are easily tempted to spend real money to save time.
Who makes it: This is the biggest hit from Supercell, helping the Finnish company achieve a $3 billion valuation.
Top in-app purchase: $99.99 for a chest of gems
Estimated daily new users: 39,814