There are a number of SDRSharp plugins that extend its functionality. Here is a collection of all the plugins and download links that I could find. The installation of most of these plugins will require editing the Plugins.xml file with a text editor such as notepad. Most files will contain a readme.txt or magicline.txt file that shows what line to add to the Plugins.xml file. Just copy and paste the plugin .dll into the SDR# folder and add the magicline line to the plugins.xml file to install the driver.
Note: Now that SDR# has updated to the .NET4.6 platform (October 2015), many old plugins that are not maintained may no longer work. However the actively maintained plugins have all been updated and are listed below.
Frequency Manager + Scanner and Scanner Metrics and Frequency Entry Package Plugin
This is a plugin package which comes with three plugins. It comes with a more advanced frequency manager than the one shipped with SDRSharp.
It also has a scanner option which can quickly scan through a group of your saved frequencies, looking for an active signal.
It also has a scanner metrics plugin, which records frequency activity to a database. Later this database can be analyzed to find out which frequencies are the most active, saving you time searching manually for active frequencies.
Finally, this package also has a frequency entry plugin, which works like the old SDRSharp frequency entry used to work. Basically, it just allows you to choose a center frequency and IF frequency easily by typing it in instead of adjusting it with the mouse.
Fast Scanner Plugin
Similar to the Frequency Manager and scanner plugin in that it automatically tunes to active signals above a certain power.
Allows programs like WXTrack to work with SDRSharp through a DDE interface.
QPSK Demodulator Plugin
Used to demodulate QPSK signals from the Meteor M2 weather satellites. Used in conjunction with LRPT decoder. See tutorial here.
DDE Tracking and Scheduler Plugin
Another plugin that allows software like WxTrack and Orbitron to interface with SDR#. This one is meant to be used with the QPSK decoder plugin for automatic scheduling of satellite passes. See tutorial here.
SDRSharp Net Remote
Allows you to remotely control SDR# through a network connection.
CTCSS Detector and Squelch Plugin
Adds a Continuous Tone-Coded Squelch System (CTCSS) decoder.
DCS Detector and Squelch Plugin
Adds a Digital Coded Squelch (DCS) decoder. Similar to the CTCSS detector.
Allows signal reception to be timeshifted to allow for time to click on a signal.
Digital Audio Processor
Adds digital audio processing features such as an improved squelcher, an audio inverter and a bandpass and deemphasis filter.
Similar to the digital audio processor shown above, but adds the ability to graphically adjust the bandpass filter in the audio spectrum of SDR#.
RDS Logger Plugin
Logs Radio Data System (RDS) data to a CSV file.
DSD+ GUI Interface Plugin
Adds a GUI interface for the popular DSD+ digital speech decoder program.
AUX VFO Plugin
Enables multiple VFO’s in SDR#. (In other words, you can tune to several stations simultaneously within the same swatch of live bandwidth)
IQ Plugin Autocorrection
Replacement for the standard IQ autocorrection. Helps improve performance on slow computers.
Audio Waterfall Plugin
Adds an audio spectrum waterfall to SDR#.
Download Here (Original plugin seems to be dead but the link is left up just in case it comes back)
PAL/SECAM TV Plugin
Allows you to watch analogue PAL TV channels in black and white through SDR#.
IF Processor & Tracking Notch Filter Plugin
Adds the ability to set tracking notch filters in the IF stage and to asymmetrically filter the IF stage.
Modified Baseband Recording Plugin
An enhanced version of the recording plugin that comes standard with all SDR# installations. Adds a scheduler, a feature to record only when there is a signal, select samplerate, and choose file output location.
Modified Audio Recording Plugin
A modified version of the default audio recording plugin. Adds a scheduler.
IF Recorder Plugin
Allows you to record an IQ file of just the current IF bandwidth. An IQ recording of just the IF bandwidth will be much smaller than one of the entire bandwidth.
CSVUserlistBrowser SDR# Plugin
Allows users to interface with the CSVUserlistBrowser plugin intended for use with Winradio products. The CSVUserlistBrowser is a program that provides a database of radio stations.
MPX Output Plugin
Allows programs like RDS Spy to work with the audio output from SDR#.
Radio Sky Spectrograph Plugin
This allows SDR# to interface with Radio-Spy Spectrograph which is radio astronomy software that allows fine control over a waterfall display.
Aviation band 8.33 Calculator Plugin
Automatically converts the current frequency input to an aviation one according to the standard 8.33 kHz channel spacing.
Frequency Lock Plugin
Simply locks the frequency settings in SDR# to prevent accidental changes.
Unitrunker Serial Based Trunking Plugin
Allows Unitrunker to interface with SDR#. For example it can be used to allow unitrunker to control the frequency setting in SDR# to following trunked conversations over various frequencies.
Passive Radar Plugin
Allows you to use the RTL-SDR as a passive radar detector.
Averages the current bandwidth. Is useful for applications such as radio astronomy.
Front End Plugins
Modified R820T FrontEnd with Manual Control and Decimation
Not really a plugin, but a modified front end interface and driver for the RTL-SDR that allows manual control over the LNA, Mixer and VGA gain stages. Also enables decimation which allows for better narrowband warefall views, and a easy control for activating a SpyVerter upconverter.
This plugin give a playback interface when playing back recorded IQ files. Allows you to view the entire waterfall of the recorded file and quickly skip to any time.
E4000 Gain Mod Enabler
A plugin which allows the E4000 Linrad gain profiles to be used in SDRSharp, via use of a modified rtl_tcp server.
Plugins that no longer work
These plugins no longer work, but may still work with older versions of SDR#. Usually they stop working because of an SDR# upgrade that requires some minor modification to the plugin, but the plugin is no longer maintained. Some provide code so there may be hope in getting these running again if someone is willing to make the changes and recompile the code.
Orbitron Plugin (Not working with 1400+)
Superseeded by the DDE Tracking and Scheduler Plugin (shown in the above list)
Allows the Orbitron satellite tracking software to control the frequency in SDRSharp. This is useful as Orbitron can automatically correct for the Doppler shift when listening to satellites.
Easy Scanner Plugin (Not working with 1400+)
Another scanner plugin similar to the scanners already shown above. Add frequencies to the database, then use the scanner to automatically find an active signal.
Audio FFT Plugin (Not Working with 1400+)
Adds a audio FFT display in the plugin window.
ScopeView Plugin (Not working with 1400+)
Adds a simple audio scope to the plugin window.
Simple Audio EQ Balance Plugin (Not working with 1400+)
Adds a simple audio EQ balance setting option box in the plugin window.
Level Meter Plugin (Not working with 1400+)
Adds a power meter for the currently tuned frequency and bandwidth.
Signal Strength Logger (Not working with 1400+)
Logs signal strengths over time of specified stations.
SDR# short-wave.info Plugin (Not working with 1400+)
Enables SW station names to be displayed within SDR#.
GlobalTuners SDR# Plugin (Not working with 1400+)
Allows SDR# to associate with a GlobalTuners.com account.
Unitrunker Trunking Plugin (Not working with 1400+)
Allows the trunking control software Unitrunker to control the frequencies in SDRSharp. This allows digital and analogue trunking systems to be followed. Note that Unitrunker can now directly interface with the RTL-SDR, so using SDR# together with Unitrunker is no longer recommended.
AutoTuner Plugin (Out of date)
Automatically tunes to signals that appear in the spectrum which are above a certain adjustable signal strength. Can also create null areas to prevent automatically tuning to unwanted signals. There seems to be only an outdated version, which is built in to an old version of SDRSharp available.
ADSB# Plugin (Missing)
Runs the ADSB# ADS-B decoding program as a plugin in SDRSharp. The main advantage to using this plugin is that you get to visually see the waterfall whilst decoding. It also adds a 1-bit CRC error check.
Download from the files section of this Yahoo group. (You will need to register first) (Note: File is gone now, still looking for updates to this plugin)
Modified ScopeView Plugin (Missing)
A modified version of the scope view plugin with Decimation, HoldOff and Hold options resides in the SDRSharp Yahoo group files section under the name TXmonitorScopeView.zip (you will need to join the group first to download).