Day Be Hoc Chu Cai - Hoc So is an excellent educational app designed for children aged 3-6 years old to learn the Vietnamese alphabet, how to pronounce the letters, and recognize the numbers. The app is developed by GFK Studio and is available for free on Android platform.

One of the key features of the app is that it includes 29 letters and 20 digits in Vietnamese, making it a comprehensive tool for learning the language. The app also allows children to learn how to write Vietnamese letters and numbers, and count the numbers. Each letter is accompanied by an illustration, making it easier for children to remember them. The sound and voice standard is high, ensuring that children learn the correct pronunciation of each letter and number. The app is also image-friendly, making it easy for children to remember what they have learned. The interactivity level is high, making learning fun and engaging for children.