Modules

Provides reports that help inspect a site's content and structure.

Shows entity/bundle counts, but no info on field usage or entity relationships.

Core block module.

Enhanced block visibility configuration.

See related core issues - this module provides a workaround until those are implemented.

Create views local tasks for views pages.

You can create menu tabs in views, but this gives you more control and lets you create secondary tabs.

Render an ERD of your site architecture.

This can be used to create a nicely formatted report, but it takes some effort and doesn't provide one out of the box.

Provides a block that shows when content was last updated.

As a block, it's not seamlessly integrated with the existing author/post date info.

Drupal core taxonomy module.