No other Android app has been downloaded more times than Gmail
High fives are in order for Google's Gmail team, as Gmail is the first Android application to notch 1 billion downloads in its belt. The feat, which actually occured a few days ago, was announced today by Google VP Sundar Pichai, who posted the achievement on his Google+ page. It was a succinct (albeit excited) recognition, though crossing 1 billion downloads doesn't mean there are a billion people using Gmail.
According to The Inquirer, the ticker on Gmail's Google Play page indicates the total number of installs instead of the total number of devices that have the app. That means a single person using Gmail on his or her Android phone, tablet, and perhaps even all-in-one gets counted as a separate download for each device.
The ticker also doesn't take into consideration inactive or duplicate accounts. This is important because Gmail comes preinstalled on almost all Android devices, so the download number is artificially inflated.
Nevertheless, reaching 1 billion downloads is still an impressive feat, even if the actual number of Gmail users isn't quite as high.