Flag

module_name
flag
Description

Handle favourites, reading lists, spam, friend lists etc.  Can be applied to any entity (nodes, users, comments etc.)  It appears as a clickable link. Can choose between page reload and AJAX when user toggles it.  Linked with views, and you can trigger events when flag count reaches a threshold.

Categories
Tested by me
Yes
Drupal 8 support
Yes
Essential
Yes