I came across this LimeLight Integration video on the MemberMouse support forum: http://support.membermouse.com/support/solutions/articles/9000020458-configuring-lime-light
In the video there appears to be a "LimeLight" option in the Payment Settings tab (see below).
Unfortunately, we aren't seeing this option on our end. See below:
Is there an extension/plugin we are missing?
Limelight integration is only available for those with a Premium account. This is likely why you're not seeing the option.
For more information on what's included in the different MemberMouse accounts you can take a look at the MemberMouse Plan Descriptions.