It connects your device to wifi automatically. Once you connect to wifi through this app it will connect your wifi automatically even when you are out of range and when you come back again in range. Some devices fail to connect to WiFi even when you are back in range of WiFi. Sometimes the only option is to switch off and restart the phone and that's when WiFi Auto Connect comes to your rescue.
Please note: The app asks for Wi-Fi password in order to automate the process of reconnecting to the Wi-Fi on behalf of you. The password stays in the app and is not shared externally.