GoTiengViet 2 is a free Vietnamese keyboard app that can be used on Android devices. The app has been officially merged with LabanKey, which is available on the Play Store. The app has many features, including the ability to suggest words with high accuracy and the option to choose from various keyboard themes. It also supports Telex and VNI input methods, which allow users to type Vietnamese with ease. Moreover, the app offers advanced Telex mode, which can significantly increase typing speed. Users can also draw accents to add to Vietnamese characters, or use shortcut keys to switch between input methods.

Note that the app requires some user information to provide its features, but it does not collect any payment information. It is worth mentioning that the app will stop receiving support on August 1, 2015.

In summary, GoTiengViet 2 is a rich-featured Vietnamese input method service that provides the best typing experience in Vietnamese. If you are looking for a reliable Vietnamese keyboard app, GoTiengViet 2 is a great choice.