Facebook has been working for several months on the planned video-chat app, which would allow users to send short video messages using a touch-screen, the FT said, citing people familiar with its plans.
Slingshot could be launched this month, the paper cited one source as saying, while noting that Facebook might ultimately decide not to proceed with the launch of the app.
Facebook chief Mark Zuckerberg has been overseeing the "top-secret" project after the social network company was unable to win Snapchat's creators, Evan Spiegel and Bobby Murphy, with its $3 billion takeover offer late last year, the FT said.
Snapchat, popular among teenagers, allows users to send smartphone photos that automatically disappear after a few seconds.
The interest in ephemeral messaging has been noted by several other Internet giants, including Yahoo, which earlier this month bought a Snapchat rival called Blink.
As a result of the acquisition, the Blink app will be shut down for Android and iOS platforms, and the team will work on Yahoo's 'smart communication products'.
While the terms of the Yahoo-Blink deal have not yet been disclosed, it was reported that the 7-member team would be joining Yahoo at its Sunnyvale, California headquarters. The team also includes Kevin Stephens and Michelle Norgan, former Google employees who created Meh Labs, the start-up that made Blink, reports BBC UK.
Written with inputs from Reuters
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