JQL Tricks plugin enhances the search functionality in Jira. It is supported on both Jira Datacenter and Cloud but works differently on both the versions, due to the architectural differences of the App framework.
On Jira Datacenter, JQL Tricks plugin adds a set of useful JQL functions. The app exposes more than 50 functions, including simple issue functions to complex issue linking & hierarchy functions. More details on JQL Tricks Plugin - DC version can be found here.
On Jira Cloud, JQL Tricks plugin adds a set of JQL aliases that can be used in JQL queries. These aliases are similar to the standard JQL fields in Jira and duplicates the functionality of complex JQL functions in the Jira DC version. More details on JQL Tricks Plugin - Cloud version can be found here.