Hello,

UTube Booster is not an original Application of YouTube, It is a third party Application that provide services like Sub4Sub, Like4Like, View4View, etc.
There is no orignal Application by YouTube that provide such services.
I would not prefer to use these kinda services because it is not the right way to grow your channel, you will get fake subscribers and once YouTube get that are growing with such services then your channel will be terminated.

Hope this helps, all the best.