I discovered this add-on over five years, and it still holds the champion title in the category. With the incredible number of website/protocol/format support, the app provides the best successful rate.
For the record, I am not saying this add-on was the perfect solution. A few annoying bugs won't be your problem, but the learning curve about the setting could be a challenge.

Très bon outil, dommage qu'il soit obligé de respecter un délai de chargement sur certains sites

nice program

A good video downloader, I just think that a "reload download" button could be useful when there is a download issue.

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It's a must-have add-on. Doesn't always work correctly with YT though.

Useful add-on, does a decent job. Only issue is that it tracks your downloads so that it can pop up a message every 100 downloads. It's a very creepy stalker'ish behavior and makes you wonder what else is being logged.

Ottimo componente, stabile e funzionale. Qualche difficoltà ad usare l'applicazione esterna con Fedora Linux, ma eccellente con il browser Firefox.

Pretty good generally, and very good for a free add-on. Used regularly

UTILE ma con qualche problema di istallazione nel mio computer

powerful and download easily

É uma ótima ferramenta para baixar videos de cursos e sites bloqueados, a interface a princípio é um pouco confusa e demora um pouco para entender os processos, precisa de uma atualização no visual, no mais é muito bom.