WP Welcome Message is the new WordPress plugin that allows you to create message using visual or HTML editor then display them automatically in a fade out or slide up view.
Splash pages are those pages that comes visible when a new visitor visits your website, generally a splash page contains information about the site, age verification or welcome message including an ENTER button which when clicked directs your visitors to the home page of your website. This tutorial is on new WordPress plugin that easily allows you to create your own splash pages and display them with in a few clicks.
Whenever someone registers on your BuddyPress site you can automatically send a welcome message, friend request, group invitation and also you can redirect to a custom page using Welcome Pack plugin for BuddyPress. You can do a lot more, go through this tutorial.