Huge funding news for Stockholm. Truecaller, the reverse number lookup directory, has raised $18.8 million (€13.8 million) in Series B funding. Participating in the round is existing investors including Finland-based Open Ocean Capital, Truecaller Chairman Stefan Lennhammer, and “a private investor who is known for his high profile Silicon Valley investments.”

The company counts 45 million users who use the service to block spam calls and identify unknown phone numbers. According to the company:

As part of the company’s ongoing commitment to expand its list of product features, the company is also announcing an integration of Yelp API data as part of its new product launch on Android and iOS, which allows users to identify millions of reviewed businesses globally. The new Truecaller release incorporates new social features to make it even easier to update contacts and get in touch with ‘people you may know.’

“Truecaller is among the most engaging applications in many high growth smartphone markets, as it helps make users more efficient in avoiding spam calls and know who is calling them. We are excited to help support the company’s growing user community,” says Shailesh Lakhani, Sequoia Capital, who has joined the board at Truecaller.

Additionally the company says:

With Yelp integration, Truecaller users can now identify local, national, and international businesses, and also view their Yelp rating. This integration takes Truecaller’s own search engine to find people and identify numbers, and combines it with Yelp’s crowdsourced business ratings to create one place for genuine and accurate information for the world to use. The ability for users to take advantage of Yelp’s local listings follows on a major partnership that Truecaller forged with Twitter to allow users to tweet and follow other users directly through the Truecaller app.

When talking about the best Stockholm-based companies, I think it’s easy for many to skip over Truecaller, since reverse number lookups aren’t as sexy as Spotify, Tictail, or Minecraft. As you can tell, this article is written a little hurried this evening (damn plans and U.S. timed embargoes!), but Truecaller’s ability to partner with Twitter, and now Yelp, places it solidly near the top. On top of that, their ability to raise money from Sequoia demands respect. It will be interesting to see where this funding takes them.