Delivery-only brands — cooked in another brand's kitchen and often delivered by third parties like Uber Eats — were proliferating even before the pandemic. But over the last year, delivery-only brands have seen explosive growth as the pandemic made delivery a more popular option. On Wednesday, Applebee’s is launching Cosmic Wings, a delivery-only brand that specializes in chicken wings and Cheetos-flavored dipping sauce. Grubhub and DoorDash won’t say how many delivery-only brands are on their platforms. In some cases, delivery-only brands have become big businesses of their own.