The Forms Tracker is a panel of the same window in which you track PDF reviews and subscriptions.

To open the Forms Tracker, choose View > Review Tracker, and then click the Forms Tracker button  on the left side of the window.

Four buttons appear on the left side of the Forms Tracker. Each one opens a different panel when clicked: To Do, History, Search Results, and Forms Library. These panels can remind you of the status of various forms that are part of your workflow and make it easy to find and reopen those forms.