It's not "completely free" because there's a premium part which has most countries in, and which were before accessible for free. But the free part works great too, and has the country I personally need. Still 5 stars for this, because most other VPN extensions don't work at all, so this is the one I'd recommend especially for linux.

分享一个便宜好用的加速器，一月不到一包烟钱，油管4K秒开https://rebrand.ly/3u8qsy

i'm sorry, your add-on isn't good enough. it's working good but expensive Upgrade (1 week= $4). not recommended, i don't trust it anymore... because my credit card cannot pay for unwanted add-on.
and what is "Free forever"? i think everyone should upgrade it every week - year.
it's scam.

It's cool addon

не работает

мошенники... бесплатные сервера работали ровно один день, потом резко все оказались заняты. Предложили перейти на премиум, оплатил, ни один из премиумных серверов не работает!
they are scammers, beware and avoid! free servers lasted exactly one day, then out of sudden became overloaded. I was proposed to switch to premium, payed for it, but NOT A SINGLE PREMIUM SERVER WAS WORKING! this is bullshit or scam. Put your money elsewhere.

An excellent VPN add-on, the only annoying thing is notification you can't turn off and which won't disappear until you click them. I mean, it's REALLY annoying, please add an option for turning them off.