Bing announced today that it has added another company – Sonar – to its Bing Fund roster.

Bing Fund was launched last year as an “angel investor with an incubator”. In August, Bing unveiled its initial startups. Now, after remaining quiet for the rest of the year, they seem to be picking up the pace a bit.

Last month, Bing announced the addition of LikeBright to the Bing Fund fold. Today, it’s Sonar. Bing Fund program manager Aya Zook writes on the Bing blog:

March is full of excitement and promise. Spring is just around the corner and people are beginning to get restless. As Austin readies itself for the geek-stampede that is SXSW Interactive, it seems a fitting time for this announcement. It will be an occasion for us to once again have the pleasure of hanging out with the Sonar crew led by founder, Brett Martin.

Over the years, we have crossed paths with Sonar across the land of tech probably more than any other startup. Whether it was TC Disrupt NYC, PSFK NYC, at our own epic pop-up gallery, SMW, and most recently Xconomy NYC, wherever we went, it seemed that the cool little periscope was right there with us. We would bring each other up to speed, and talk about “hey, wouldn’t it be cool to work together?” And go our separate ways until the next serendipitous encounter.

Sonar is a social discovery app that tells users when their friends and friends’ friends are nearby, and as the company puts it, “reveals the hidden connections and small world moments you might have otherwise missed.”

The app takes advantage of social and location data from Facebook, Foursquare, Twitter and LinkedIn to give users context about the people they’re near.