This app contains 204 countries with their capital currency area population language and many more information.
And its categories by 7 continents with their countries.

Information included:
1. Countries flag
2. Countries name
3. Countries capital
4. Countries population
5. Countries area
6. Countries President name
7. Countries language
8. Countries calling code
9. Countries timezone
10. Countries inter TLD
11. Countries currency

This will help you to increase your general knowledge about all country in the world.