Updated from 12:16 p.m. to reflect the name of the product is Yahoo Livetext, not simply Livetext.
At an event in New York, Adam Cahan, Yahoo!'s senior vice president of Video, Design and Emerging Products, unveiled the service. "Every single platform shift begins with a change in our communication style," Cahan said. "What we looked at are our phones are in every possible context. We asked this question why do we feel so uninhibited when we text but not with video and phone? We want to bridge the gap of the simplicity and ease of texting and the expressiveness of video."
Yahoo! Livetext, which has a profile screen extremely similar to Snapchat, is live video that features text without sound, allowing users to see reactions from the people they are texting. The service is similar to FaceTime, in that a user can see the reaction of the person they're communicating with, but it also offers texting and emojis.
The app goes live tomorrow in the U.S., U.K., Germany, France and Canada on both iOS, as well as Android. More countries are set to come later, said Arjun Sethi, Yahoo! senior director product management, during the unveiling.
The messaging space has attracted enormous amounts of attention in recent years from users, investors and the media.
Messaging services have also taken an enormous bite out of SMS usage and revenue in recent years.
Revenue from U.S. text messaging came in at $21 billion for 2014 and is projected to decrease steadily, according to research firm eMarketer. The firm also said the quantity of texts sent has also peaked, with it projected to hit 7.3 trillion in 2015, down from 7.5 trillion in 2014.
Facebook also offers its own messaging app, Messenger, which it has heavily pushed. Messenger, the number one free app on the App Store, has more than 700 million monthly active users.
Yahoo! recently reported
that showed little year-over-year growth as the core business continues to struggle.
Adjusted earnings came in at 16 cents a share on $1.08 billion in revenue, excluding traffic acquisition costs. In the second quarter of 2014, Yahoo! generated $1.04 billion in revenue.
On Wednesday, Yahoo's stock was trading down slightly to $37.65.
The news of the mobile messaging app was first reported by Re/Code's Kara Swisher.
--Meg Garner contributed to this article.