The big picture: Apple's App Store and Google Play both saw an increase in the number of developers pushing their revenues to over $1 million for the first time. App development on the digital storefronts continues to grow as many developers begin switching to subscription-based rather than ad-based models.

According to an analysis report from Sensor Tower, Apple's App Store has produced 164 millionaire developers in 2018. The analytics firm which focuses on Apple and Google digital storefronts also said that the Play store only had about half as many new developers that reached $1 million in revenue this year.

Since Apple takes a 30-percent cut, Cupertino raked in well over than $50 million from the newly minted millionaires alone. According to the company's recent press release regarding its expansion into Austin, Texas, the App Store is responsible for creating more than 1.5 million jobs in the US. Most of those are independent app developers.

Sensor Tower's analysis also indicated that the industry is continuing to see significant growth.

"The number of publishers with their first $1 million or greater year on the U.S. App Store grew by approximately 15 percent over 2017, when we found that 143 achieved this milestone," the report reads.

Although Google did not turn out as many millionaires, it saw similar increases percentage-wise. A total of 88 developers made their first million from Google Play in 2018. Compared with 2017's number (71), this is about a 20 percent increase.

Apple has been pushing developers to switch to a recurring subscription model versus in-app advertising, which seems to be paying off.

"Both of the categories with the greatest year-over-year growth in terms of numbers among new million-dollar publishers---Lifestyle and Health & Fitness---were ones where there is a strong focus on generating revenue through in-app subscriptions, whether it be from fitness tracking, guided meditation, premium dating services, etc," Sensor Tower analyst Randy Nelson told Business Insider via email.

Gaming, which made up about one-third of the million dollar apps, saw some revenue growth, but health and fitness and other non-gaming applications watched their revenue grow by about 57 percent this year. This increase was primarily attributed to in-app subscriptions.