Overall, it works very well, although both extension and apps were glitchy when first released. No ads, even in the free versions. Ditto for VPN, mail, drive, and calendar. I'm a Proton Unlimited subscriber now, and use the Pass extension on both of my Raspberry Pi computers. Hope Proton eventually comes out with stable apps for Linux distributions on the Pi's ARM architecture. That said, you still need to secure your browser in Settings>Privacy & Security, disable "personalization" features, limit or curtail retention of cookies and browsing history, and use a private window when your device is shared or if your using a public device.