Log in as a different user from the SharePoint UI. The ability to log in to a SharePoint site as a different user was taken away in SharePoint 2013 but we put it right back there again.
The best thing is that it’s completely free, just download, install, activate and use.
What it does
Alt Login puts back the menu item to allow users to sign in with a different set of credential.
Download
You can download the solution package from the linked zip file :
Install
The package actually consist of 3 solution packages (WSP files) scoped at the Farm, Web Application and Site Collection. You don’t need to install all 3 solutions, instead just choose the variant with the scope that best suits your needs.
So, if you want to enable Alt Login for your entire farm then deploy the farm scoped package. If you want Alt Login enabled for specific Web Apps then deploy the Web App scoped package or if you would rather that Alt Login was only made available for specific Site Collections then deploy the Site scoped package.
The solution packages can be installed in any of the standard ways such as via PowerShell.
Feature Activate
Then all you have to do is activate the feature at the appropriate scope and Alt Login will be made instantly available to all users accessing sites within that scope.
Kaboodle Software 