Tiếng Anh 123 is an Android app developed by BeOnline Co. Ltd. It falls under the category of Education & Reference and offers free access to a range of English language learning resources. The app provides mobile access to the online English learning website TiếngAnh123.com, which is one of the leading online English learning platforms in Vietnam.

The app offers a range of features including the ability to record lessons, complete exercises, and take part in online competitions. To use the app, an internet connection is required. The app covers a wide range of topics such as English learning through videos, basic English at levels 1 and 2, basic grammar, pronunciation, vocabulary, TOEIC test preparation, online scoring, and more.