Movie ticket app Atom Tickets of Santa Monica has raised a $50 million Series B round from investors, including Lionsgate, Walt Disney Co. and Twentieth Century Fox.

Atom Ticket’s investors see the app as a way to fill unsold theater capacity.

The app can be used to purchase tickets and concessions, as well as invite friends to specific movie showings. Atom Tickets also provides movie reviews, trailers and movie summaries.

“More than four billion seats go unsold in theaters each year,” Lionsgate Vice Chairman Michael Burns said in a statement. “The Atom team (has) developed a state-of-the-art app that offers exciting new opportunities to pre-purchase tickets and concessions as well as paving the way for the successful introduction of dynamic ticket pricing.”

Launched in 2014, the Atom Tickets app is available on Android and iOS, but only in select regions. The company is gearing up for a national rollout later this year.

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.