Add-ons

DragonByte Mail is a professional mailing list mod with advanced subscription management features. Additionally, it has a newsletter feature that highlights your most popular threads.
Uses
 DragonByte Mail is the perfect solution for any forum who wish to send out large quantities of mail to users on a mailing list. It lets admins and users have fine-grained access to subscriptions, and also sends out automated newsletters with powerful algorithms for determining popular content.

Major Features:

Analytics Data Gathering: Data is gathered regarding how many of your users open your emails, and how long they read them for. This can be disabled per mailing list. This data will power advanced delivery features, ensuring maximum engagement with your content.

[tl] Social Groups is a complete social group system for the XenForo 2 forum with excellent features and a user-friendly interface. 
Info: social groups

Key features [tl] Social Groups:
* Ability to create unlimited categories and nested categories for groups. 
* Ability to create unlimited custom fields for each category. Custom fields will be displayed in the group details. 
* Show custom field positions, data types, create PHP callbacks for fields, 
* Ability to group members and easily manage member roles and permissions in a group. 
*Developments. Each group has the ability to create their own events.
* Subsections. 
* Support avatars. Each group has the ability to easily upload your avatar 
* Cover Photos. Each group has the ability to easily upload its cover 
* Displays statistics for each group. 
* And much more