Nextdoor is like Facebook but for neighbors: a private network to find a baby sitter, borrow a cup of sugar, organize a block party or spread word of a break-in. Nextdoor / May 23, 2013 SAN FRANCISCO -- Nextdoor, which wants to be the go-to social network for neighborhoods, is rolling out an app for the iPhone and iPod Touch. Nextdoor co-founder and Chief Executive Nirav Tolia said he expects the mobile app to fuel growth and increase the amount of activity in neighborhoods. Nextdoor is being used by more than 12,600 neighborhoods in 50 states, he said. Some 30% of visits to the Nextdoor website come from mobile browsers. It's not the first time a start-up has tried to network neighbors, but Nextdoor is one of the first to gain momentum. An app for the iPhone and iPod Touch was the most requested feature from Nextdoor users, Tolia said, and took about eight months to build. The company is working on an Android app that should be out this summer, he said. Neighbors can now send urgent alerts about suspicious activity or share a photo of a lost dog from the iPhone app. Tolia said Nextdoor users who tested the app over the last couple of months checked it more often and posted more often on Nextdoor. "We think with the mobile app we are going to get more word-of-mouth virality," Tolia said. Nextdoor is homing in on the 'hyperlocal' market Nirav Tolia launches Nextdoor, private social network for neighbors