Like when using public wifi, what can I install/use on both my Android phone and Windows laptop to make it impossible (or very difficult for someone who is not an expert) from seeing what websites i visit?
You can route your connection through a VPN. This will encrypt the connection from your device to the VPN provider, therefore making it impossible for the wifi router owner to scan your traffic. See Understanding VPNs : How VPNs can be used for anonymization? for more info.