Kraken implementation

I was searching the forms and the docs for information about Kraken. The docs only state how to install the addon, not how to implement it. Once I install the addon and provide my aip key, does the addon just work and automatically start compressing my uploaded assets? I have not tried to install the addon yet and was wanting to get an answer before I even tried to sign up for an api key. I also did not provide any other information because it really is irrelevant. Thanks!