Exactly what I was looking for!

I tried several of the bigger YT plugins before and all of them annoyed me more or less. This one finally did the job: Responsive embedded videos on mobile devices while keeping a maximum size on bigger screens. Simple and effective!
You can use all YT parameters like “&rel=0&showinfo=0&modestbranding=1” and even embedding YT playlists is easy by using “videoseries?list=URL”. Great!

2 suggestions:
Could you add a privacy option using the “youtube-nocookie”-URL?
The plugin settings should be placed under “settings”, not under “plugins”.