Do you want to have some fun, learn something and help others?
Free Rice allows you to do this. Pick a subject from vocabulary, literature, paintings, chemistry, geography, math and many others. For each correct answer you give, you will earn 10 grains of rice. After a few successful rounds, your rice will be a sizeable mound and be transformed into real rice which is donated to people in need. It's completely free.
My best to you all,