There are plenty of opportunities for native English speakers to tutor people in English in foreign countries. The benefits for them in this exchange is clear. They get the opportunity to learn an important skill which can effect their economic outlook for the rest of their lives. What you can get is less clear. Teaching in a foreign country is a great way to learn a language by interacting with individuals who speak it as a first language. You also get the enriching experience of being in a foreign culture, and to make some money while doing it.
When you sign a contract for something like this, you usually promise to stay for a year. Most of the countries which require things like this are countries which are still underdeveloped, so you could expect to be doing this in countries in Africa, South America, and Asia. All of these opportunities can be a truly enriching experience for you, to learn about a foreign land, their language, and their way of life; all by helping to make their lives better.