Free Mini Sundae at Freddy's - To celebrate National Frozen Custard Day, Freddy's is offering a free single-topping mini sundae in the app from Aug. 7 through Aug. 11. No purchase necessary. Just download the Freddy's App and sign up to get your FREE Mini Sundae reward. If you're already registered in the Freddy's App, you will receive your National Frozen Custard Day reward in your account starting on Monday, August 7th. Limit one mini single-topping sundae reward per device. Only available through the Freddy's App 8/7-8/11. Locator