The ComScore research firm released a new report on the state of the U.S. mobile market that suggests most people aren't downloading a lot of new apps for their devices, even as their total app usage time continues to rise. The report's most notable takeaway for game makers? Roughly 65 percent of those surveyed by ComScore downloaded less than one new app per month for their smartphone, which seems like bad news for any mobile developer hoping to drum up downloads of their next game. While the problem may be assuaged by platform holders like Apple taking measures to boost discoverability of new games and apps, it might not be enough: ComScore's survey of smartphone user habits suggests the majority of mobile users may simply be content to find a few apps they like and stick with them. According to the firm, those surveyed spent nearly 75 percent of their smartphone time using their four most-used apps. Their top app sucked up nearly 42 percent of their smartphone time, and the number one app most popular app was -- you guessed it -- Facebook, followed by other social media apps. Games like Candy Crush Saga and Words With Friends were among the ten most-used apps for those age 35 and older, though they accounted for an average of between 1-2 percent of the total time spent with mobile apps by those surveyed.