You can choose resolutions up to Full HD, and it is entirely legal and safe from malware. 2. Best for Your Camera Roll: Documents by Readdle

Videos are stored in the Library > Downloads section of the app and can be watched without an internet connection.

If you want to save a video directly to your iPhone's (Camera Roll) using a link, the Documents by Readdle app is the gold standard. How To Download YouTube Videos On iPhone

The simplest and most secure method is using . This is the only way supported by Google to download videos for offline viewing directly within the app.