Whether you're too tired to cook or it's too cold to go out, food delivery apps are lifesavers. But did you know there are certain hacks to them that'll make your life even better? Apps like Grubhub, Uber Eats, and DoorDash offer perks to their users that go beyond just ordering what you want. You can also refer your friends to get extra savings on your own orders and find tons of discount codes online. And, just in case you didn't already know, Starbucks delivers via their app! Make the most of your ordered-in meals with the following food delivery app tips.