Tasks lists are a really nice way to get a quick overview of the completion status of a given feature or user story:
AutoTask will automatically create a task list on referenced issues, that will automatically be checked whenever the referencing issue is closed. In the above screenshot, issue #496 simply has a #495 reference in the body:
Since the task was closed, its corresponding item in the #495 issue task list is checked automatically. If you now closed #498, it would become checked right afterwards too via AutoClose.
AutoClose works with cross-repository references too, so you can automatically notify completion status on other repositories.
Install the OctoHook.AutoTask nuget package on your Web API project:
PM> Install-Package OctoHook.AutoTask