Tags Buddy Pro is a free app that allows you to view and copy tags from any video on YouTube. The app can also generate a list of keywords based on the tags you see.

The best thing about this app is that it works for any video on YouTube, even if you don't have any subscribers. The app will work for you, no matter what you have done.

All you have to do is to enter the URL of any video on YouTube, then select "Extract Tags" and you will get all the tags, along with their associated keywords, in a list. You can then copy them and use them in your videos.