Maybe it's me as I realize that my skills in this area may not be comprehensive enough to use this extension but I installed it with no problem. Then I tried it and it said I needed a companion app and gave me two options for that. I tried both options, even having to tweak my security settings to allow the .pkg file extension. Then it finally allowed me to choose the format/conversion except being a laymen there are so many options that seamed so similar like mp4 1mb vs mp4 2mb. So by one I tried the ones I recognized as to not overload/overburden my macbook or the server or whatever can get overloaded. None of the formats, not even one actually downloaded. I gave up, tried another similar extension. One click to download the extension, then one click to select the format then a third and final click to download the media. That's it! The other one worked. Maybe this extension is simply too sophisticated for my average/adequate skills. I'm assuming it's me but maybe this review will help developers think about us laymen when creating extensions in the future. Cheers!

Spyware. VDH asks you to install an app. DON'T DO This. Your IP address is changed and rerouted to a bot with IP 37.1.188.237, located in Manila, the Philippines, GPS location 14.61 120.97. Various sites will refuse entry, telling you you're on a bot and at an abnormal location. Some virusscanners know this and act.I you are on Linux and have Redshift: the color temperature of your screen will give the time and temperature of the Philippines. To search a nearest shop location (entering postal code): doesn't work anymore. In case you have installed that app: only switch VDH on when needed and switch off after use, but never start your computer with VDH switched on. Or remove VDH and reinstall without the app? I'm not sure if the app is removed together with VDH.

made youtube videos unplayable

Allows you to download ONCE and then every video afterward will require you to install a third party application - even if you go to download the same video again, demonstrating that it's not just a certain type of video that requires the "companion application"

This screams malware.

Para descargart cualquier video pide instalar una "aplicación auxiliar" sin esa aplicación auxiliar no se puede descargar ni reporducir nada. Buscaré otro complemento que realmente sirva.

Descargaba muy bien y sin problemas hasta que me pidieron dinero y como no dí me da muchos problemas y no puedo descargar muchos de los vídeos. O ES GRATIS O ES DE PAGO.

DO NOT USE. Absolute scam. Requires you to install their software (could be a virus), took a long time to download, and then had a massive QR code in the corner... the only way to remove the code is to pay them. Use another addon or just use the online video downloaders.

Simply does not work.
After installation I tried to download a video from YT (a free video; no music; no film; etc.). DownloadHelper asked me to install a companion file. After some research and re-thinking I pressed the button and there was -- nothing. An error message appeared (from github) that there was no such a repository.
So, that's it for me: I uninstalled this add-on.

下载的视频没有声音

Used to be great..now is terrible. The companion app constantly needs updating; however it never lets you know. The aggregating is a HUGE problem; it take hours to do this!! FIREFOX; please recommend another BETTER app!!

This extension is not working with latest Firefox version.

podre. precisa de um app adicional pra baixar videos. demora horrores pra um video de 50 minutos. Não recomendo. Procure um software mais confiável e eficiente, pois esse é inútil

QR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR codeQR code FU!!2!!!@!!

does not show up anywhere after installing it so no way to use it = CRAP

They put a QR in the corner of every videos that you download with it.

this barely works, and its supper suspicious. NOT Recommended; proceed with caution!!!