Elastic Stack has useful plugins already packaged as part of the X-Pack component. However, other plugins are available in the industry and could be used to get more insight into Elasticsearch. Some of those external plugins are as follows:

• Head plugin: Classic monitoring and health plugin for Elasticsearch clusters. Not available with X-Pack in favor of the Kopf plugin
• Kopf plugin: Monitoring and health plugin that is included as part of X-Pack along with Elastic Stack
• BigDesk plugin: Packed with X-Pack and is capable of generating live charts and statistics for the Elasticsearch cluster
• Elasticsearch-SQL plugin: Not available as part of X-Pack but could be used for querying Elasticsearch similar to RDBMS
• Paramedic: Packed with X-Pack by default