Plugins
Multisite Featured Image
With the WordPress Multisite Featured Image plugin you can create “featured images” for each site in your network.
Stealth Login
Custom Login Stealth Login protects your wp-login.php page from brute force attacks by requiring a authentication key and code in the URL.
WP.com Image Feed Widget
WordPress Image Feed Widget plugin allows feeds with image embeds to be shown in the sidebar of your site, or anywhere widgets are allowed in your theme.
Calendar Date Picker
Calendar date picker, a simple WordPress plugin that does one thing. It adds the jQuery UI Datepicker plugin to the edit screen.
SEO Media File Renamer Pro
SEO Media File Renamer Pro is a plugin that gives you full control of your uploaded WordPress media files.