Betternet is a simple, free and unlimited free VPN.
The system works much like any of the competition. Click a "Connect" button, and within a few seconds you're allocated a new IP address, improving anonymity and maybe allowing you access to sites you couldn't otherwise reach.
This worked well for us. We were connected quickly, there were no DNS or other privacy leaks that we could see, and browsing speeds weren't noticeably different.
We also found that torrents weren't blocked, though beware: if you try to download gigabytes of data then we wouldn't be surprised if the company cuts you off part way through, or maybe throttles your connection to help other users.
One very obvious down side is that there's a very limited choice of servers on the mobile apps, and our Windows client gave us no choice at all. We connected many times over two days and always got a Swiss IP.
Betternet needs to pay for this somehow, so of course there are ads. Our Windows client opened a new browser window to display ads whenever we clicked Connect, and the mobile apps offer apps to install, or videos to watch. But you're not forced to do that, and overall the package is much less intrusive than it might have been.