This plugin speeds up the process of logging in as another user. When logged in as admin a new menuitem will be injected into you user menu.
Clicking the menu item will open up a modal with a search input that allows you to search on the username. If any matches are found the results will be shown in the modal
Clicking the username immediately logs you in as that user.
Once logged in as another user you get a new session and do the testing or support work you need to do.
When done, click your usermenu again choose 'Return to real user'
Use the moodle plugin installer to install this plugin, or unzip the plugin in the /local folder of your moodle instance and make sure it uses the foldername loginas