I frequently see requests in the forums for a way to see, at a glance, which assignments are waiting to be graded. Many other LMSs have such a feature, and it's absence in Moodle seems glaring. In asynchronous environments, teachers can't know which activities are waiting to be graded without either opening each activity to look or being flooded with notification e-mails.

There are a few blocks designed to help teachers know which activities need grading, but they only monitor a few types of activities for ungraded submissions. The most comprehensive one, AJAX Marking Block, has a couple of bugs but is no longer being maintained by its developer.

Moodle needs a marking/grading manager in core which provides a standard method for developers of new activity types to have it included in the types of activities being monitored for submissions. Perhaps the AJAX Marking Block would be a great starting point, so you wouldn't have to start from scratch.