(https://www.eff.org/sites/default/files/https-everywhere2.jpg)
HTTPS Everywhere is a Firefox and Chrome extension that encrypts your communications with many major websites, making your browsing more secure.
https://www.eff.org/https-everywhere (https://www.eff.org/https-everywhere)
Https everywhere FAQ
https://www.eff.org/https-everywhere/faq (https://www.eff.org/https-everywhere/faq)
...and it will make your browsing activity more slower, just compare it between https and regular http, you'll notice slight browsing speed decreased while using https connections. ;)