There really aren’t any. Running a VPN service costs money, and if you’re not paying, they’re probably using you the user to make money. Be it by selling your data, cryptomining, adding you to botnets, etc.
The closest you could get would probably be to use a freemium VPN. Most of them are limited, but I found Windscribe and ProtonVPN to be the best. Windscribe limits your bandwidth which varies depending on if you verify your email or tweet a promo, and they also force you to use their proprietary app. However, they’re probably the fastest freemium VPN I’ve used. ProtonVPN on the other hand is slower but doesn’t cap your bandwidth and allows you to use OpenVPN.
Sadly in the case of VPNs with regarding to privacy there isn’t much option available to you. Cheapest would to get a $3-5 dollar Good Privacy Focused VPN like Mullvad or IVPN and Proton VPN as you said…
Windscribe is pretty good as you said…
I’m currently using Atlas it works well for my requirements its not the most privacy friendly options out there but it works well for me (Its a paid service)
I do plan to switch to something better like Mullvad which is very good and they just had recent black Friday sale where it was dirt cheap. Even without it the price $5 is very good. I don’t use VPN too much but if you the one who uses it alot more Its much better to get one if you can afford because not all services with focused on privacy are free sadly.
You can keep using windscribe they have good reputation and there PC Client is Open Source.
And One More free VPN service you can look is RiseUp VPN they are funded by only donations and its free and open source and available for all devices android and PC.
If you want to compare the Best privacy focused VPNs
Here’s a good chart link for you
I hope it will help and sorry for the long post lol