The website version works like a charm, I love it, but the extension doesn't works at all: it only allows you to download in 360p, but once you download the video and try playing it, it only shows an error message saying "The following content is not available on this app, watch this content on the latest version of YouTube".

The extension no longer works, it does not fulfill its purpose of allowing you to download videos

Редкостная чушь,которая с "ОК" грузит файл не более 200Мб и сбрасывает загрузку...

Опять всё сломалось и долго не исправляется... Кнопка на ютюбе не работает, всегда качает 5мб видео с ошибкой. Ждем исправлений

The big problem is that it refuses to download videos in 480p. It used to be able to do this but sometime around 2022-2023 it was downgraded. Now, even for videos with 480p viewing available, it will only allow 360p as the highest SD quality. If 720p is viewable, that will still be available for download, but still no 480p.
It has been this way for a while now so it must be intentional. There are also other apps that allow 480p downloading so it's a choice the creators/managers of this add-on are making to deny the option for 480p downloads.
I would have given this 5 stars easily back when it allowed 480p downloads. Now the most I can reasonably give is 3 stars. Good for 720p downloads and if you're will to accept 360p instead of 480p, it'll work.
2024 Update: Now it spams your browser every single day begging for money. I have downgraded the score from 3 stars to 1 star. DO NOT DOWNLOAD.

Не работает, зато навязывает установку, отправку уведомлений и т.д.

a présent l'outil de téléchargement ne est complètement absent.

Was great for years. Something changed and it does not work anymore. Deinstalled and sent note in hope they repair.