DLB Caddy is a browser extension (sometimes called a plugin) that helps you fill in downline builders in a fraction of the time it normally takes. It can also tell you about all the downline builder slots you could fill in (because you're a member and have an ID) but haven't.
Semi-automatically because you still have to visit the downline builder page. But DLB Caddy will pick up any referral IDs you have and populate any empty downline builder positions with IDs it knows. As time goes on and DLB Caddy learns more of your IDs, so it will fill in more more automatically.
DLB Caddy also has an associated website and members area. Here you can do and view things related to your stored data.