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:

Exports reports and search results directly into the native MS Excel format (xlsx).
Current Usage: 835
E-mail API for CiviCRM to send e-mails through the API
Current Usage: 784
Extension to support General Data Protection Regulation
Current Usage: 746
Provides a way to keep Mailchimp Lists and CiviCRM groups in sync.
Current Usage: 695
Provides tools for signing up, managing and tracking volunteers
Current Usage: 654
Tokens for CiviCRM including formatted address block (with country formatting), today's date, userID, phone, membership & relationship token
Current Usage: 627
Twilio and CiviCRM integration allows delivering single and mass short message service (SMS) messages through its Twilio Gateway to mobile phone users. Download Link: https://github.com/civicrm/org.civicrm.sms.twilio/releases/latest...
Current Usage: 616
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: 608
Tokens for emails: Supports events, contribtion pages, profiles, forms, petitions, addressing couples, nicknames. Links include checksum.
Current Usage: 545
A log viewer for the CiviCRM debug log, showing a summary with links to a detailed view of each log entry.
Current Usage: 538
Sometimes CiviCRM can be real tough to debug. Especially when you are getting fatal errors, but only by some users, and you can't recreate the problems. This utility will send you a detailed email when a CiviCRM fatal error occurs.
Current Usage: 536
Mobile application for few specific actions in CiviCRM Current feature includes: * Contacts - Search Contacts - Add/Update/View Contacts - Proximity search for contacts * Events - participant search and checkin * Survey - Search for suvery - Record survey responses    ...
Current Usage: 534
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: 531
Allows Drupal's cron to invoke CiviCRM's cron.
Current Usage: 501
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: 496