Insight Follow Manager (List Diff Tool)

Insight Follow Manager is a tool that allows users to compare their "following" and "followers" lists in order to find out "people they follow but don't follow them back" and "people who follow them but they don't follow back"!

Despite the name of the tool, the tool can be used to compare 2 lists related to anything and find out what items belong to one list and don't belong to the other one!