Apple kicked off the mobile apps craze five years ago and the industry continues to gain momentum. App stores run by Apple and Google offer more than 700,000 apps each. Because of the growing range of choices, it is estimated that consumers spend an average of two hours per day with their apps. And they’re spending money on them, too. However, this may only be the beginning.

“Global revenue from app stores is expected to rise 62 percent this year to $25 billion, according to Gartner,” reports the Wall Street Journal.

“The apps industry has matured in some respects,” notes the article. “Some of the Wild West tactics of five years ago — like scams to accrue more downloads — have given way to more order as Apple and others tighten their rules. App developers are more methodical about marketing their apps and focusing on the few apps that work best.”

But even amidst the growth, experts still consider this the beginning stages of the industry, projecting further growth. The apps industry “is like cars at the turn of the last century,” said Simon Khalaf, chief executive of mobile analytics firm Flurry Inc. “You see the growth of roads and know they’re going to be big. But it is still early days.”

Apple and Google are in a relative tie regarding number of apps available and overall usage by consumers, but Apple makes more money than any other by a more than three-to-one margin. Other companies with app stores include Microsoft, BlackBerry and Amazon.

Another point of interest is the app’s reach, no longer just made for use on a smartphone, but also for tablets and TVs. This means more time spent on the apps, according to Flurry, which reports that “in the past two years, consumers have doubled the time spent with apps to about two hours a day.” However, it’s challenging to sustain that interest on one app: “people churn through apps fairly frequently, making it hard for developers to retain users,” according to the article.

Furthermore: “About 63 percent of the apps used daily now differ from those used daily a year ago. Moreover, consumers focus on a handful — roughly eight apps — at a time.”