Foursquare just checked into the top three mobile apps.

The New York startup, headed by CEO Dennis Crowley, is behind only Facebook and Twitter in the mobile app rankings, a new Nielsen report shows. Foursquare’s unique monthly visitors in the US reached 10.4 million, a 118 percent increase from last year.

“We’ve added more users this year than in all of the previous years in the company’s history combined,” a company spokesperson said.

Pinterest was the fastest-growing social network, with online visitors up more than 1,000 percent year over year.

Facebook topped all social networks online and on the mobile Web.

Google+, the search giant’s social network, made strides with 26 million monthly visitors, up 80 percent, ranking seventh online. It placed fourth in mobile with 9.7 million monthly mobile users, a gain of 86 percent.