Just four years after it was launched, Google Photos has reached and surpassed 1 billion users. The photo organizing and editing service is Google’s ninth product to reach the milestone and joins Android, Gmail, YouTube, Google Maps plus Google search.

The service has however, reached the billion mark faster than other Google services. This is because just five months after it was launched in 2015, it had already acquired 100 million monthly users and it was able to hit the 500 million users mark in two years.

Google Photos started out as a spin off of Google+ which proved to be unsuccessful and was unceremoniously shut down this year. However, according to Fast Company, the fact that it was a separate app allowed it to mine some of the best underlying technology of Google+ without being saddled by its less popular features.

Google is now chasing the 2 billion user mark for the service and as part of the efforts, it has launched Gallery Go a lightweight alternative to the main Google Photos app.

Anil Sabharwal, the Google VP who led the creation of Google Photos, had this to say, “We’ve crossed this really critical milestone of a billion monthly users, and Gallery Go is how we think about the next billion.”