AKEYO POWER AO
The POWER Animation Overrider is a new AO system which makes it much easier and more fun to maintain your collection of custom avatar animations. http://www.akeyo.de/help/aoHUD.html

What I understand is that you must buy the animations but for what use ? What are you going to do with them ?

It's the best AO I have seen. If you spend a lot of time in Second Life then you do things like this.