Pokémon Go, once a viral sensation all over the globe, hasn’t fallen off the map. In fact, the augmented reality game is earning more money than it ever has before.

According to mobile analytics firm Sensor Tower, Pokémon Go had a record year in 2019, taking in an estimated $900 million through in-app purchases. That means Pokémon Go has surpassed its launch year in revenue after seeing a drop off in both players and spending back in 2017. It’s a rare comeback feat for a free-to-play game, many of which are flash-in-the-pan successes and fade into obscurity.

Normally, free-to-play games either come out of the gate with a huge boost in revenue and popularity and then slowly decline as time goes on, or the app starts small and builds toward a peak of popularity and financial success. Pokémon Go didn’t follow either trend. After a blockbuster 2016 in which the game became a viral sensation and earned $832 million, Sensor Tower says its popularity declined sharply. In 2017, the game only generated an estimated $582 million.

But through the introduction of new features — like raid battles, trading, and improved AR camera effects — Niantic carved out a dedicated and highly lucrative niche in the mobile industry. By the end of 2018, in-app purchase revenue for Pokémon Go once again soared, this time to an estimated $816 million.

Sensor Tower estimates Niantic has pulled in more than $3.1 billion to date on Pokémon Go. Although not all of that money goes straight to the app developer, as the company has a revenue sharing agreement, which has never been made public, with The Pokémon Company, of which Nintendo owns a significant share.

Still, Pokémon Go’s success has helped Niantic become a leading augmented reality developer and one of the most successful mobile app makers in the industry. The company has since opened up its app-building and AR toolset, the Niantic Real World Platform, to third-party developers. It’s also built a Harry Potter AR game in partnership with Warner Bros., as well as a reboot to its original AR game Ingress called Ingress Prime.