In addition, Heyward says Whisper has over a million app opens every hour, and over 10 billion monthly page views from users in 187 countries.
Whisper has raised more than $60 million since its 2012 launch.
In April, the Venice, California-based startup revealed it had more than 10 million monthly active users, and 1 million app opens per hour. That means its userbase has doubled in the past eight months.
In April, a 16-month-old Whisper competitor, Secret, went out of business. A memo written by Secret's CEO, David Byttow, stated that the app had 15 million users at its peak.
There's a big difference between monthly active users and total users. Monthly active users visit a website or mobile application at least once every thirty days.
Total users are the number of people who have ever used an app, even just once. As of February, another Whisper competitor, Yik Yak, had a few million (but less than 10) monthly active users.