Today ProtonVPN released its iOS app to the public, which is available for download on the App Store for both free and paying customers.

It can be used with iPhones and iPads to encrypt online data, joining a suite of three other custom apps available for Windows, MacOS, and Android.

In a blog post on its website, ProtonVPN said: “ProtonVPN for iOS is now available for those of you who are ready to take back your digital privacy, visit blocked sites, and keep your personal data safe, even on public WiFi,

“This represents a major milestone in our journey towards helping our users take back their online privacy and freedom.”

The new app uses IKEv2 encryption, for “higher speeds and stability, even in adverse mobile network conditions’. It also has all the advanced security features found in the other apps.

Secure Core is one feature that routes traffic through multiple servers before leaving ProtonVPN’s network, making it even harder for third parties to track your online activities.

The iOS app also includes a VPN kill switch, which prevents your IP address from being exposed during connection drops, and built-in support for using Tor with the VPN.

ProtonVPN is associated with ProtonMail, an email encryption service set up by former CERN scientific researchers. The team at ProtonMail decided to build a VPN service after attending the Second Asia Investigative Journalism Conference in September 2016.

It was there that they realized the necessity for using a VPN to protect online privacy and circumvent censorship blocks. Today ProtonVPN apps are used by a million people, according to the company’s website.

In its blog post, ProtonVPN thanked users for their support but encouraged those on the free plan to upgrade to a premium account in order to “sustain the service”. It said: “As much as we would love for it to be the case, privacy and security unfortunately are not free.”

Those upgrading from the free version are advised to do so from the company’s website rather than the App Store to avoid the extra costs incurred by Apple.

As ProtonVPN expands its privacy offering, we are wondering whether a native app for Linux could be on the cards next.

If you’re interested in knowing more about ProtonVPN read our comprehensive and impartial review.