package-loading-notifier notify when packages are loaded.
package-loading-notifier can be installed through MELPA.
To enable package-loading-notifier, add following in your .emacs file:
(require 'package-loading-notifier)
(package-loading-notifier-mode 1)
To add more packages for package-loading-notifier, set package-loading-notifier-packages variable.
(setq package-loading-notifier-packages '(org magit yasnippet))