ControlMySMS sends random texts periodically and pays you for each text it sends. It can pay up to $12/month by letting it do its thing. I don’t have to do anything at all once it is installed and set up. It may require a data/texting plan on your phone (SMSogram is a good way to circumvent that if you don’t want to use your own phone plan) in order to receive the texts from them to earn money per text.
This is available worldwide!