PARIS — A new mobile game made in a Market Square office went on sale last month, and it’s already selling worldwide.

Stack King, a game for iPhones and iPads, is the result of 10 months of programming, composing and testing. The game has sold hundreds of copies through Apple’s virtual App Store, where users can download games and other programs for their portable Apple devices.

The game, which has received rave reviews, was made by Appy LLC, one of Maine’s first app developers and certainly the first in rural Western Maine.

It’s a simple game. The player stacks objects higher and higher with rows of boxes flying back and forth. The player taps the screen to stop the row’s movement just as it’s above the stack, adding another layer. Like Angry Birds and other mobile games, it doesn’t make much sense, but it’s addicting just the same.

Game-review website Nine Over Ten called the game “casual gaming perfection.” Another website, Daily Joypad, gave the game four of five stars.

In addition to a single-player game, Stack King offers a two-player feature, which lets players on separate phones or iPads compete head to head. The game even allows them to talk to each other while they compete.

“The research those guys put in was incredible,” Appy partner Fred Garbo said of the development crew. He said once they realized the game should have a two-player mode, the development extended the project another five to six months.

Stack King was programmed by Matthew Crandall, a 2000 graduate of Oxford Hills Comprehensive High School who got a computer science degree at Worcester Polytechnic Institute. After graduation, he worked at eBay for a short time. Crandall said he had been working on iPhone apps independently before forming Appy with his old friend Fred Garbo.

Garbo has a history in entertainment, and runs Fred Garbo’s Inflatable Theater Company, a traveling stage act. He has performed on Broadway and on “The Late Show with David Letterman.” In the 1980s he was Barkley, a dog character on “Sesame Street.” He has lived in Oxford Hills throughout his career, he said, traveling to New York for much of his work.

Since October, Stack King has been the top project for Crandall, Garbo and others, including Paris dentist and Appy partner Myung Kim, tech consultant Aaron Im, graphic artist Lonnie Houghton and Kim’s teenage daughter, Evangeline, who composed the music.

“We’re hoping that this company grows,” Kim said. “There are a lot of talented people in this area.” He said he hopes the company can eventually provide a means for local college graduates to stay in the area, rather than heading to Boston or California for technology jobs.

Crandall said he decided to develop on Apple products for the increased chance of sales. Developers of Apple apps have made $2.5 billion selling their programs through Apple, which gives developers 70 percent of the cost of their applications. That means Appy gets 70 cents each time someone buys their 99-cent game in the App Store.

It’s not much, but the most successful apps get millions of downloads. Angry Birds has been downloaded 250 million times, many by paying Apple customers.

But Appy is in a crowded marketplace with an estimated 500,000 apps. Its next project is called Say Anything, and it turns iPhones and iPads into mobile bill boards, allowing them to send messages to people across the room, in other vehicles on the highway and other opportunities.

The app will be free, they said, as a way to get Appy’s name out there. They’re planning an advertisement that mimics a famous scene from the movie “Say Anything,” in which John Cusack plays a song for a girl on a boombox he is holding outside her window.

In the ad, the guy will be holding up an iPad, with his message scrolling across the screen.

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