Usar o APKPure APP
Obter o APK da versão antiga de WiFi Password Viewer para Android
WiFi Password Viewer ajuda a visualizar sua senha wifi.
'WiFi Password Viewer' helps you view your wifi password, which you cannot see in device default setting.
You need to ROOT your device to use 'WiFi Password Viewer', as this only works on rooted devices (needs super-user permissions) because your device stores Wi-Fi passwords when you connect to a new Wi-Fi network. You are not able to access the previous passwords and retrieve them unless you have super-user permissions. Checkout here for more information on root: http://www.androidcentral.com/root