MinTube
Minimized/Floating Youtube
Download
You can also get It Here, or go to bit.ly/mintube
in your mobile.
Source
There are two versions of the app : v0.95 and v0.91.
The only difference between v0.95 and v0.91 is that v0.95 shows icon on hiding and v0.91 shows a resized player on hiding the whole video player. All the other functionalities are same.
The above download link was for v0.95.
You can get v0.91 of the app here.