Just over four years after its initial announcement, Google Photos has reached one billion users, reports Fast Company. The photo organizing and editing service is Google’s ninth product to reach the milestone, joining Android, Gmail, YouTube, Google Maps, and, of course, Google search.

However, unlike many of these other services, Google Photos hit the target in a relatively short period of time. Within five months of its announcement at Google I/O 2015, the service had already amassed 100 million monthly users, and it hit the 500 million user mark two years after launch.

Google Photos drew on some of the underlying technology of Google+

Despite being one of the stock apps that comes on every Android device, the success of Google Photos was not guaranteed. It was originally a spinoff from Google+, one of Google’s most public missteps that shut down earlier this year. However, as Fast Company notes, being a separate app allowed Google Photos to mine some of the best underlying technology of Google+ without being saddled by its less popular features.

As part of its efforts to now hit the 2 billion user mark, the team today launched Gallery Go, a lightweight alternative to the main Google Photos app. “We’ve crossed this really critical milestone of a billion monthly users, and Gallery Go is how we think about the next billion,” Anil Sabharwal, the Google VP who led the creation of Google Photos, told Fast Company.