Extensions are installable packages which give CiviCRM new functionality, and this directory provides a centralized list of extensions which the CiviCRM community has created.

Further resources:

E-mail API for CiviCRM to send e-mails through the API
Current Usage: 850
This extension does nothing by itself but is required by a number of other extensions developed by MJW Consulting.
Current Usage: 822
Civisualize is a civiCRM extension which let you visualize your civiCRM data with the power of dc.js and d3.js. dc.js let users create graphs which enable filtering through the data with just a click on the graphs giving you a lot of powers....
Current Usage: 761
A log viewer for the CiviCRM debug log, showing a summary with links to a detailed view of each log entry.
Current Usage: 735
Tokens for CiviCRM including formatted address block (with country formatting), today's date, userID, phone, membership & relationship token
Current Usage: 722
Provides a way to keep Mailchimp Lists and CiviCRM groups in sync.
Current Usage: 674
Have you ever wanted to rearrange the contact summary screen? Move the most important information to the top? Remove unnecessary stuff? Create a simplified layout for your volunteers and interns but a more robust layout for your fundraising team? This extension will let you do just that.
Current Usage: 668
This extension facilitates uploading CSVs via the CiviCRM import interface. Useful for bulk uploading events or campaigns etc. The civicrm api entity can be set to, for example, Event or Campaign. (Note that for entities like Contribution Pages you need to use API names - either ContributionPage or contribution_page). The same permissions apply as for any api create call....
Current Usage: 666
Once installed, an 'API Key' tab will be available on contact screens for which you are authorized to manage the API key for this contact. You are authorized either if the contact if yourself, or if you are an administrator with the 'edit all contacts' permission....
Current Usage: 637
Provides the latest version of the API (Application Programming Interface) for CiviCRM.
Current Usage: 635
Provides tools for signing up, managing and tracking volunteers
Current Usage: 562
The CiviMobileAPI extension (com.agiliway.civimobileapi) is a CiviCRM component that allows to use a mobile application CiviMobile.
Current Usage: 503
Allows Drupal's cron to invoke CiviCRM's cron.
Current Usage: 503
Event Calendar Extension allows you to view all CiviCRM events in a calendar by month,day,week.
Current Usage: 501
This extension allows CiviCRM to send emails and process bounces through the SparkPost service. It was designed with the following goals and/or features:...
Current Usage: 448