Claire Foy as Queen Elizabeth II and Matt Smith as Philip Mountbatten, Duke of Edinburgh in The Crown a Netflix Original

Netflix has become the top grossing iPhone app in the U.S. for the first time, driven by a change that allowed users to subscribe to the streaming service on their mobiles, according to a report released Monday.

In September 2015, Netflix introduced a feature for Apple users allowing them to sign up to the service through the app rather than via the website.

This has helped it gradually get to the top of the rankings, a report by app data company SensorTower showed. Since in-app purchases were introduced, weekly net revenue has grown from less than $50,000 to nearly $2.9 million.

Monthly iOS revenue for Netflix in the U.S. has been increasing at an average of 19 percent per month since last November, SensorTower said. Over the same period, monthly iOS revenue for rival service Hulu in the U.S. increased an average of 3 percent per month.

Netflix has been focusing on growing its mobile product as it continues to push for new users. Last month, the company introduced a download feature to allow users to watch certain shows offline.

In its third-quarter earnings, Netflix said that it had gained 370,000 net memberships in the U.S. and 3.2 million internationally, a total of 3.57 million, beating the 2.3 million the company forecast. This helped quell investor concerns of a continued slowdown in subscriber growth for the company.

Netflix also occupies the number one grossing spot on iPhone in India, Mexico, and Colombia.