Chuyển đổi đầu số - đầu số mới is a free Android app developed by DmobiSoft. It falls under the category of Utilities & Tools, and is designed to help users update their phonebook in light of the 11-digit to 10-digit subscriber conversion mandated by the Ministry of Information and Communications (MIC) in Vietnam.

The app offers a range of useful features, including automatic display of all phone numbers that need to be updated, the ability to select a list of phone numbers to update according to the new prefix, support for all 11-digit prefixes of the five operators, automatic backup before conversion, and support for restoring old phone numbers. In addition, the app can handle phonebooks with over 1000 entries and can automatically select numbers according to the conversion schedule. The app is simple, fast, and offers complete data security.