Been using iTubeStudio for six months now, nothing going wrong with anything on my iMac. They have good IT. In the beginning I couldn't get the green tab to work that showed up at the top of downloadeable videos, had to copy the URL and paste it in the app. But they fixed it in a few weeks, works fine.
I use iTubeStudio. Used to be a lot of free ones, some would leave a "button" in your page header and just click on it.
Have you used the web to actually search for one?
Been using iTubeStudio for six months now, nothing going wrong with anything on my iMac. They have good IT. In the beginning I couldn't get the green tab to work that showed up at the top of downloadeable videos, had to copy the URL and paste it in the app. But they fixed it in a few weeks, works fine.