Ok. So the money isn't really free but sometimes these websites do get you money back. Mostly, I scan a reciept and get a couple of dollars back. After a week I made almost $30. So if you want to try some of these, I have a few links for you. (And yes, I do get a small amount of money back into my account when you use my link.) :)
This is an app and a website. Before I go shopping I look at the food I can get a rebate on and unlock the rebate. After I shop I scan in the receipt. Easy. I only unlock the foods I do use (obviously). This site is basically an online coupon, meaning, I don't have to clip the coupons. You can also link your loyalty cards. I like Ibotta because it's easy and has groceries and products I use.
I have Ebates on my toolbar so whenever I shop online I automatically earn cashback. So far I have over $50 in my account. You can earn back anywhere from 14 % to 40%. Eaaaaaaaaasy.
If you like to take surveys, InboxDollars is the one to try. There's a lot of surveys, games, offers, videos etc which range from one cent to $5 or more. You can use the website and the app to earn cash. I'm at $20 right now and only do a minium of one survey a day. There are ways to earn for just clicking on an email.
Another easy way to earn money back. With Swagbucks you can earn points searching the web, buying online through their link, watching videos (mostly movie trailers) or clicking through emails and then redeeming for gift cards etc.
Scanning in any receipt (up to 14 days old) and earn coins. When you reach 1000 coins you can cash out for $5.