I want to clear out any app I no longer use in my docker. The docker "add container" link has a number of docker apps I want to clear out. How do I achieve this? I've already remove the apps from docker and cleared the the docker image by deleting it. Thanks for the help. 

Click on the docker you want to remove once loaded clock on the X next to it. that simple

 

Or apps, previous apps.  Check off what you want gone then hit delete