"The peak is 4.9 downloads a month for iPhone owners, and 6.2 for those packing an Android handset"
Are these the figures for someone that has just bought a new smartphone and does it includes "updates. "
After the fad has worn off and you have made your little collection of usefull things, I think the majority would then be downloading about 3 or 4 per year..... Unless were talking about the under 16 year old group.