Here are some of the Plugins for Rails developed and maintained at Usergenic:
- acts_as_change_aware - Allow your models to keep track of attribute changes during the life of the object.
- better_conditions - Extends the form of values provided to the :conditions option for ActiveRecord finders to enable the composition of more complex logical expressions without the need for custom SQL partials.
- find_by_association - Something we feel ActiveRecord should already provide, this plugin makes referencing associations and associated objects’ associations as easy as referencing standard column attributes in conditions hashes. Never code another line like :something_id => Something.id again!
Or browse the Rails plugins section of our public subversion repository for more.