Security researchers suggest to combine simultaneously both a private browsers and a VPN apps, both on your computer and an your Android phone, to enhance security.
VPN and HTTPS proxy
VPN browsers automatically unblocks websites, encrypts your internet traffic, and makes you anonymous. Unlike all other web browser apps for Android, VPN Proxy Browser is not bloated with unnecessary features. It just focuses on unblocking sites and encrypting your internet traffic.
As with most browser “VPNs,” the VPN is in fact a secure HTTPS proxy. But it gets the job done, has no data limitations, and is fast. Most VPN browser include built in ad blocker, with load pages even faster.
5 best free VPN browsers
Opera
Opera is a free unlimited and built-in VPN. Opera’s native ad blocker effectively helps you get rid of intrusive ads and loads your pages faster. Opera provides a private browsing mode and an adjustable night mode, plenty of options and functionalities.
More info: https://play.google.com/store/apps/details?id=com.opera.browser
Cake Web Browser
Cake is a free, worldwide VPN. The VPN provides military-grade encryption without tracking, throttling, or bandwidth restrictions empowering you to search with peace of mind. Cake doesn’t ask for your name or email.
Cake Web Browser’s privacy features include anonymous browsing, private tab time bomb, passcode protection, Do not track, ad & tracker blocking, etc. It also includes a dark mode that integrate with your system settings.
More info: https://play.google.com/store/apps/details?id=com.cake.browser
Browsec
Browsec is a free VPN that protects your online privacy while accessing the Internet. It is your number one app if you want protected web surfing with unlimited VPN.
Free version is limited to 1mbps debit and 4 locations (Netherlands, Singapore, United Kingdom and United States). This app is not using an HTTPS proxy but a slot of our phone VPN, so it can be complementary to your current VPN if you already have one.
More info: https://play.google.com/store/apps/details?id=com.browsec.vpn
Aloha Browser
Aloha Browser Turbo is a free unlimited VPN with military grade encryption, data compression and no logs. It also includes native ad-blocker, a screenshot blocker, and a passcode lock.
Speed excellent, but be aware that the free service is ad-supported. So it blocks some ads on one hand, but generate some ads on the other hands.
More info: https://play.google.com/store/apps/details?id=com.aloha.browser
Avast Secure Browser
Avast Secure Browser is a free feature-packed private browser with AdBlock and VPN designed to make secure browsing fast and easy to use. Avast’s private browser automatically blocks ads and trackers that slow you down and includes advanced security and privacy features such as free VPN, anti-tracking, full data encryption, PIN lock, and more for the best private browser experience on Android devices.
However, no clear no-log policy is mentioned by Avast.
More info: https://play.google.com/store/apps/details?id=com.avast.android.secure.browser
Other secure browsers
Tor
Tor Browser for Android is the only official mobile browser supported by the Tor Project, developers of the world’s strongest tool for privacy and freedom online. Tor Browser is 100% free and open source
Tor is not really a VPN, but it is close enough to one and useful enough that we feel it worth mentioning here. All Tor browser connections are routed through the Tor network, which is to say they are forwarded through at least volunteer-run “nodes,” with your data being re-encrypted each time.
Detractors say Tor is slow and 20% of traffic is spied at the last node.
More info: https://play.google.com/store/apps/details?id=org.torproject.torbrowser
Conclusion
Opera is the best option as it free, complementary to your current VPN, unlimited and includes both ad-block and privacy mode.