From the homepage:
Real-Time Monitoring
From monitoring individual cluster nodes, to viewing real-time threads, ElasticHQ enables up-to-the-second insight in to ElasticSearch cluster runtime metrics and configurations, using the ElasticSearch REST API. ElasticHQ’s real-time update feature works by polling your ElasticSearch cluster intermittently, always pulling the latest aggregate information and deltas; keeping you up-to-date with the internals of your working cluster.
Full Cluster Management
Elastic HQ gives you complete control over your ElasticSearch clusters, nodes, indexes, and mappings. The sleek, intuitive UI gives you all the power of the ElasticSearch Admin API, without having to tangle with REST and large cumbersome JSON requests and responses.
Search and Query
Easily find what you’re looking for by querying a specific Index or several Indices at once. ElasticHQ provides a Query interface, along with all of the other Administration UI features.
No Software to Install
ElasticHQ does not require any software. It works in your web browser, allowing you to manage and monitor your ElasticSearch clusters from anywhere at any time. Built on responsive CSS design, ElasticHQ adjusts itself to any screen size on any device.
I don’t know of any compelling reason to make ElasticSearch management and monitoring difficult for sysadmins. 😉
If approaches like ElasticHQ make their lives easier, perhaps they won’t begrudge users having better UIs as well.