The iPhone’s share of quarterly global smartphone app downloads stood at 29% in the second quarter of 2012, significantly below the 47% attributed to Android smartphones, according to new data from ABI Research (www.abiresearch.com).

"The iPhone’s download share tends to see a lot of seasonal fluctuation, but over the past year or so it has stayed surprisingly resiliently between 30% and 37% of the total," says senior analyst Aapo Markkanen. "In our estimates the second quarter represented the first time the iPhone dipped below 30%. The iPhone 5 will most likely cause a second-half hike to the download count, but that may be of a rather temporary nature."

The main reason for the declining market share is Apple’s clampdown on download bots earlier this year, which some developers utilized to manipulate their charts positions. For example, app-marketing firm Fiksu has published data indicating that at the high end of the download chart the bot squeeze may have alone wiped off even one-fourth of daily volumes.

For Android, the bots haven’t been as big a factor to begin with, owing to Google’s different app-ranking methods, as well as to the fact that in its app economy there is still far less money changing hands than on iOS. As another reason points to the growing prominence of the iPad.

"It’s notable that among the iOS apps the momentum is also shifting up the value chain and towards iPad applications, and this change is happening definitely faster than what Google is experiencing," Markkanen says. "We estimate in the first half of this year the iPad saw over five times more app downloads than all Android tablets combined."