You can find general plugin settings in this tab.
By default plugin comes with support for built-in post types post and page. When you globally activate plugin, reactions will be deployed to posts and pages. In addition to this, WP Reactions supports custom post types provided by other plugins and themes. You can choose available post types from list and save settings. After that operation your reactions will be deployed to these post types as well.
Reaction limitation per users
By default, all users allowed to react only once. We keep tracking their reactions in cookies and do not allow react twice or more. But in case of you want your site users to react more than once, you can uncheck this setting.