Dear Samsung users, according to your description, Samsung mobile phones support the installation and use of third-party software in the Android version (APK) format. If you need to download a software application, I suggest you try it: 1. Use the browser in the mobile phone menu to surf the Internet and directly search for the required software to download and install. 2. Download the installation package in APK format with a computer and connect the mobile phone with a data cable. Operate the mobile phone, find the installation package in the application-My file, and click the Install button after running. 3. Download a market software first, such as Android market and Machine Front market. If it can't be installed and used, I suggest you try it as follows: 1. I suggest you uninstall and reinstall this software. 2. Unknown source is not open: Set the-Security-Unknown source check box, and then try to reinstall; 3. If other third-party software can be used normally, only this software can't have compatibility problems with the mobile phone system. If you have any comments, suggestions and comments, please click: support.samsung.com.cn/survey.