Kids’ Mobile Entertainment & Apps, the latest report from market research company The NPD Group, has found that gaming apps dominate usage among US kids, followed by music apps.

Gaming is the most popular type of app downloaded, with the chosen device used by a child containing approximately 10 gaming-related apps on average. The majority of mobile entertainment devices used by parents and kids have fewer than 20 apps that have been downloaded specifically for a child, with 7% having more than 60 apps for a child.

Music, however, dominates when it comes to overall downloading, with games coming in at a distant second place and video falling in third place. A full 61% of all kid-friendly downloads to a mobile entertainment device are music-related. The remaining types of downloads, which include ringtones, TV shows and movies, make up less than 10% of all downloading activity.

The report also cites that 82% of all apps downloaded for children were free. However, those who have purchased an app for their child are willing to spend almost twice as much as they are currently spending, with the willingness to pay for an app among device users increasing with the age of the child.

Free and inexpensive apps are driving downloads, with 75% of respondents saying the free nature of many apps is the highest motivating factor driving app acquisition. Other motivators include recommendations by family and friends, the childs’ request/desire for the app, and the apps’ affiliation with a character or personality.

NPD industry analyst Anita Frazier says free content is cannibalizing sales in many entertainment-related industries and these gaming experiences are competing for time and dollars spent among the much broader casual gaming audience.