"The importance of mobile has grown tremendously over the past five years," Herman Lee, senior manager of professional services at App Annie, wrote in a July 23 blog post.
The average phone had 93 app downloads in 2019, the study found, and average use per day increased nearly 50 percent from 2.1 hours in 2015. The gain is due in part to faster and more reliable internet connections, App Annie researchers wrote.
Among the countries that have seen an increase are the U.S., India, Indonesia, Pakistan and Russia, according to the study.
Herman added in the blog post that as app and general mobile phone usage have risen, "so have the speed and degree to which these apps can rise to the top — about one-third of Top 100 most downloaded apps are new entrants each year."
TikTok, for example, has seen some of the highest year-over-year app growth in the U.S. The social media app has been downloaded more than 2 billion times worldwide, app data analytics website Sensor Tower reported in April.
The app was downloaded more than 87 million times in June alone, making it No. 1 on Apple's App Store and the Google Play store for that month, Sensor Tower found.
TikTok has seen such massive growth because it combines various elements of social media, entertainment, education, advice and more, App Annie researchers said.
The average TikTok user spends 16 hours and 20 minutes per month, or about half-an-hour every day, on the app; that's up from 5 hours and 4 minutes in August 2018, the study found.
Apps with the most monthly active users in 2019 include Amazon, Apple Music, Gmail, Google Maps, Facebook, Facebook Messenger, Instagram, Netflix, Snapchat and YouTube, according to App Annie.