There are over 250 apps in the Google Play Store that pop up when you search for VPN, but not all of them are worth downloading. Even more - most of them you should stay far away from, and never install on your device.
Some countries - especially those ruled by a dictatorship- always try to spy on thier citizens in order to keep them under control.
VPN were developed to help you keep your privacy. Take NordVPN for example, it has no-logs policy and uses a military-grade-encryption, In simple words it makes it impossible for your governor to spy on you. On the other hand a free VPN will record your activities and serve them on a golden platter to the first client.
I recommend you check out this website so you learn more about how VPN search on google play was manipulated and how dangerous free VPNs can be https://vpnpro.com/blog/how-to-manipulate-google-play-rankings-and-get-280-million-installs/