ProtonVPN is a a VPN from the makers of Proton Mail. Proton mail is a security-conscious mail server based in Switzerland and ProtonVPN is simply put a logical extension as VPN.
There are numerous VPN possibilities on the market today, but rarely does one find one which has a working and free version as well.
While I personally recommend we all pay those 8$ per month for the PLUS version of the VPN, the free version is enough for somewhat secure-ish basic browsing. Do not think however that you are safe from spying though!
The advanced versions have P2P support and integrate with TOR perfectly. So in case you need an actual secure VPN this is probably one of the best options out there.
Still… if you don’t have any VPN install the free version at least and if you have a ProtonMail account you can simply use the same username and password.