David Marcus, vice president of Messaging Products at Facebook, speaks on stage during the annual Facebook F8 developers conference in San Jose, California, April 18, 2017.

The Facebook executive leading its messaging products said the company will streamline its Messenger app this year because its design has become "too cluttered."

The number of Messenger video chats also doubled in 2017, vice president David Marcus said in a post.

The company added emoji characters and other elements in 2016 and 2017 to enhance the Messenger user experience but not all have worked out as planned, Marcus says.

"Over the last two years, we built a lot of capabilities to find the features that continue to set us apart. A lot of them have found their product market fit; some haven't. While we raced to build these new features, the app became too cluttered. Expect to see us invest in massively simplifying and streamlining Messenger this year," Marcus wrote in the post, titled "Six Trends for 2018."

At the same time, Marcus sees Messenger and the broader messaging market, which also includes Facebook-owned WhatsApp, becoming more visual.

"I predict visual messaging will fully explode in 2018; people will expect a super fast and intuitive camera, video, images, GIFs, and stickers with almost every conversation. Even in the workplace where conversations can be more serious, we see people embracing emojis and video to help drive a point home," Marcus wrote.

"There were 17 billion video chats on Messenger for the year - two times as many as compared to 2016," he wrote.

Messenger currently has 1.3 billion monthly users. Facebook CEO Mark Zuckerberg also said last week that the company would be making a "major change" to users' news feeds to emphasize more "relevant content," which could result in people spending less time on the platform.