You can download applications in several categories.

Windows

Add-on
click for info
Description
BoincTasks An advanced and powerful BOINC GUI
CPDNSpy Stats/Benchmarkprogram. Only for CPDN!!!
BoincView Advanced BOINC manager for networks
BoincLogX BoincLogX creates detailed logfiles for all BOINC projects.
BOINCcalculator Show details of CPDN jobs
SETI@BOINCWatch A SETI@Home/BOINC client watcher! User statistics powered by BOINCStats
BOINC Client Configuration Windows GUI for editing the client configuration file
BOINC Monitor A desktop gadget that shows the status of running tasks
SETI@BOINCWatch(.NET) A SETI@Home/BOINC client watcher! User statistics powered by BOINCStats. But now built with the .NET environment.
SETI@home-MapView SETI@home-Mapview creates skymaps for the BOINC projects SETI@home-II, Einstein@home and Astropulse.
BoincSpy Views BOINC project statistics
SETISpirit SETIspirit is free add-on tool for SETI@home users which provides information about the tasks, the SETI@home project status, workunits and credits, statistic charts and a detailed sky map.
SETI@BOINCWatch(.NET 2.0) A SETI@Home/BOINC client watcher! User statistics powered by BOINCStats. But now built with the .NET environment.
ThreadMaster Control max CPU usage and prevent overheating (not specific to BOINC)
BES Control max CPU usage and prevent overheating (not specific to BOINC)
SQL Setup for BoincSpy Stores Workunits into SQL database
TThrottle TThrottle throttles CPU usage to keep its temperature below a limit you select.

Linux

Add-on
click for info
Description
BOINC Monitor Plasmoid to show BOINC status on the KDE desktop
Diet BOINC A no-graphics, lightweight XScreenSaver compatible alternative for BOINC screen saver
BOINCSTAT Command line view of BOINC status
CPU limiter Limits the CPU usage (good for laptops)
Boinc bash script Boinc state displayer
BOINCprog A BOINC project progress monitor
boincctl Script to start boinc at boot time.
BOINCTail BOINCTail displays the status of jobs running in the BOINC environment in a 'tail-like' way.
MultiTail Multitail shows several simultaneous tails in different curses windows.
BoincTasks An advanced and powerful BOINC GUI (requires Wine)
boinctop top like view of boinc status
SETI@Boinc Tracker SETI@Boinc Tracker is a GUI Client for Tracking Boinc CLI Client!
Boinctray A system tray application for monitoring the BOINC client
rc.boinc (Slackware) rc.boinc - Slackware Startup Script
boinc-suse Init script for SuSE 9.2 and 9.3
boinctui Fullscreen text mode manager for BOINC
KBoingMgr A Linux/KDE replacement for the standard BOINC Manager

Mac

Add-on
click for info
Description
BOINC Statistics Lets you check BOINC stats from the Mac OS X Dashboard
BoincTasks An advanced and powerful BOINC GUI (requires Wine)
Seti Check Revolutions Boinc state displayer. Only for seti@home!
SETI@Boinc Tracker SETI@Boinc Tracker is a GUI Client for Tracking Boinc CLI Client!
BOINCMenubar 2 Mac GUI for BOINC
CPDNSpy Linux/Mac Stats/Benchmarkprogram. Only for CPDN!!!

Mobile

Add-on
click for info
Description
BoincTasks Mobile BOINC graphical interface for mobile devices (Android, iPhone, iPad)
AndroBOINC BOINC graphical interface for Android devices

Web browser toolbars and plugins

Add-on
click for info
Description
BOINC User Statistics Widget Widget displays statistics for BOINC projects (requires the Yahoo! widget engine)
BOINC Server Status Yahoo! widget adds the BOINC Online Scheduler image to your desktop.
SAH User Statistics An extension for Firefox (works only with 1.0 to 1.5; may work under Mozilla) that displays your stats for SAH
BOINC Statistics Shows your statistics for any BOINC project (requires the Yahoo! widget engine)

Web applications

Add-on
click for info
Description
Boinc LCS Shows the current state and other information from an unlimited number of BOINC clients connected to the Internet.
BoincPHP5-GUI Monitor and control Boinc from a web browser
GOINC GOINC: A Google homepage module for keeping tabs on BOINC.
SETI@home/BOINC progress status Show your SETI@home/BOINC progress on your homepage
Progress Thru Processors Facebook-based interface to BOINC
BOINC Milestones Facebook application that posts credit milestones in your Status
Forum signature showing jobs in progress A PHP script that generates a forum signature showing jobs in progress