richardphelps

This plugin allows users to chat in real time using AJAX. Users can connect with any other users.
Use the [bp-instant-chat] shortcode to embed the front end chat on any page.

BuddyPress Instant Chat

Instant chat plugin for BuddyPress allowing user to connect and talk in real time.

WolfieZero

Pushie allows you to send push notifications from your self-hosted WordPress blog to your 
device.
All you need at the moment is Boxcar installed on your device (only iOS at the moment), 
setup an account then create a provider. With that API information, you can then get push 
notifications sent to your device whenever you have a connection to the internet.
Features 
* Instant push notifications to Boxcar 
* Notification on new comments 
* Notification on new pingbacks
Requirements 
* Your WordPress installation needs cURL support
<h3>Donate</h3>
If you wish like this plugin, use it for a site that makes you a profit or are a commercial user then please donate. See http://wolfiezero.com/wordpress/donate/ for more info

Pushie

Push notifcations to your device on certain events

BuddyPress Instant Chat vs Pushie