Placer.ai, which uses smartphone tracking data to help businesses make decisions, announced the closure of a $4 million funding round today. The funds will be used to expand its service for tracking and predicting foot traffic and people’s movements and to grow its sales and marketing teams.

The company said it obtains its data through the 100 popular smartphone apps that use its SDK and that it can anonymously but accurately track the movements of 60 percent of Android users and 40 percent of iOS smartphone users in the United States.

Alongside the funding news, Placer.ai announced the launch of a free version of its app that can share limited foot traffic movement details about virtually any business in the U.S.

Placer.ai aims to tell users not just who visits a business but where they came from and where they go after they leave. Machine learning is then used to make predictions about customer data or visitation trends.

Initial Placer.ai users include CBRE, Caesar’s Entertainment, tech company Oath, and the Santa Cruz boardwalk in California.

“We’ve decided to focus on commercial real estate, where we’re seeing a lot of adoption around: ‘Which tenants should I bring in?’ ‘How healthy are they?’ ‘Where should I acquire a shopping center?’ And a lot of these questions we help answer,” cofounder Noam Ben-Zvi told VentureBeat in an interview.

The $4 million funding round was led by IrishAngels Ventures, with participation from Array Venture and Stage Venture Partners.

Placer was founded in 2016 and has 35 employees in offices in Los Altos, California and Tel Aviv, Israel.

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