I want to add here that beside of earning tokens, another useful thing is to farming boosters.
For token, you use topeleven.com but for boosters, you must go play from facebook.
There, under the line of your friends, it's the 3 kind of boosters and a pack of money.
I don't go for the money (it's not worthy, it's only a small amount) and for moral boosters.
Only for red and greens.