Blighty

This plugin monitors installed WordPress plugins on your installation. It notifies the admin (or other email) when updates are available. Plugins can be excluded from monitoring.

Blighty Pluginator

This plugin monitors installed WordPress plugins on your installation for updates and notifies via email when they are available.

Johan van der Wijk

This plugin disables all WordPress updates (core, plugins and themes). This can be useful if you have multiple environments such as a live and staging server and you don’t want your users to use the update functionality.
This plugin not only disables the update mechanism for the core, plugins and themes, but it also removes the update menu item from the left navigation menu in the admin dashboard.

Disable Updates for WordPress Core, Plugins and Themes

Disables the WordPress update checking and notification system for all core, plugin and theme updates.

Blighty Pluginator vs Disable Updates for WordPress Core, Plugins and Themes