Applet is an application that can be used without downloading and installing. It realizes the dream of "at your fingertips", and users can open the application by scanning or searching. It also embodies the concept of "run away after use", and users don't have to care about whether to install too many applications. Applications will be everywhere and available at any time, but there is no need to install or uninstall them. For developers, the threshold of small program development is relatively low, and it is not as difficult as APP, which can meet simple basic applications, and is suitable for offline shops of life services and the conversion of low-frequency applications that are not just needed. The applet can realize seven functions, such as message notification, offline code scanning and WeChat official account correlation. Among them, through WeChat official account association, users can jump between WeChat official account and applets. Because there is no entry for the applet.