There are sites, and most of them are faucets, so basically all you need to do is put in "bitcoin faucet rotator" into google or whatever you want to use and
just farm the faucets it shows you. You won't get paid in any decent capacity, and you'll maybe make a few cents to a dollar a month, so personally I'd skip out on doing that unless you can really make use of the additional pennies that can be given to you.