https://www.drupal.org/project/login_redirect_per_role
Set the page shown to users after login, such as a dashboard.
https://www.drupal.org/project/masquerade
Log in as another user - great for testing during development and troubleshooting reported issues from an account.
https://www.drupal.org/project/r4032login
Redirect 403 response to login form. If access is denied, make it easy to log in.
https://www.drupal.org/project/social_auth
Login with social media accounts.
https://www.drupal.org/project/workbench_access
Restrict content authoring by site section.