Lovers of a particular McDonald's favourite will be salivating when they discover the burger is being offered at a buy-one-get-one-free special. But you'll have to be quick to take advantage, as the special will soon disappear. The famous burger joint is letting customers double up on the Double Filet-O-Fish tomorrow, August 17, solely on the McDonald's app.

That means you can get two of the classic burgers for just £5.29 if you're ordering through the app, according to The Sun. The offer is available for delivery or collection but to get it you'll need to download the McDonald's app, which is free on the Apple App Store or Google Play. And you will also need to be aware that the offer is subject to availability of stock in the franchise's restaurants.

If you order via home delivery, you'll have to pay a delivery charge of £1.99, a service fee, and a small order fee if your basket is under a tenner in total.

The Double-Filet-O-Fish was only released in July but has now become a permanent menu item thanks to its popularity. It features two Pollock fish patties coated in crispy breadcrumbs with creamy tartare sauce and melted cheese inside a steamed bun.

Its introduction onto the menu was significant because it was the first time the Filet-O-Fish recipe had been changed in half a century.

This offer is only on tomorrow (Sunday) - but if you miss out, not all is lost. The restaurant has revealed it's got a brand new offer coming on Monday, where Macca's will offer a Double Cheeseburger for just £1.59. The deal will be available both in McDonald's restaurants and through delivery.

How can you get McDonald's Deal Drops?

The Double Cheeseburger is the latest Deal Drop from Maccas.

Every Monday, McDonald's app customers will get a prompt to reveal their deals on the app or on email.

Each deal can only be used once per customer, the deals will then drop into the Rewards and Offers section on the app.

They can be used both for delivery and in restaurants.