McDonald's Free Ice Cream Promotion Marred by App Glitch

A McDonald's promotion for free ice cream cones to celebrate National Ice Cream Day went awry over a glitch with the fast food giant's mobile app.

McDonald's offered a free vanilla cone to its app users Sunday. But after several users complained to McDonald's on Twitter that the app wasn't working, McDonald's told them to instead simply ask the cashier to honor the promotion. McDonald's tweeted that the company was trying to resolve the issue and promised to have its app "back online soon."

The Oak Brook, Illinois-based company didn't immediately respond to a message seeking comment on the status of the app Monday.

McDonald's is set to roll out a new app aimed at improving the speed of orders later this year.