Graylog is described as 'open source syslog implementation that stores your logs in Elasticsearch. It consists of a server and web interface written in Java that accepts your syslog messages via TCP or UDP (or GELF messages) and stores it in the database' and is an app in the OS & Utilities category. There are more than 50 alternatives to Graylog for a variety of platforms, including Linux, Online / Web-based, Windows, Mac and Self-Hosted solutions. The best alternative is Kibana. It's not free, so if you're looking for a free alternative, you could try Logstash or Fluentd. Other great apps like Graylog are Datadog (Paid), Logtail (Paid), Open Web Analytics (Free, Open Source) and Splunk (Freemium).
Datadog is a monitoring service for IT, Dev & Ops teams who write and run applications at scale, and want to turn the massive amounts of data produced by their apps, tools and services into a unified view of IT infrastructure. 120+ Integrations!.
Splunk is software that provides unique visibility across your entire IT infrastructure from one place in real time. Only Splunk enables you to search, report, monitor and analyze streaming and historical data from any source.