Quoc Ky is an Android application that allows users to look up the national flags of countries around the world. Additionally, the program provides a brief introduction to each country, including the name of the capital, political institutions, monetary unit, and population. Users can also test their knowledge of national flags through the program's quiz feature.

The user interface is simple and easy to navigate. The flags are organized alphabetically by country name, and users can quickly search for a specific country using the search bar. The program also includes a quiz feature that allows users to test their knowledge of national flags.

Overall, Quoc Ky is a useful tool for anyone looking to learn more about national flags and the countries they represent.