Native Forge app
GanttBoard runs entirely inside Atlassian Cloud. No external servers, no data leaving your tenant, no third-party analytics, no telemetry. It uses only your Jira permissions (read:jira-work, write:jira-work, read:jira-user) and passes Atlassian's security review as a "Runs on Atlassian" app.
Most competitors (BigGantt, WBS, Structure.Gantt) are Connect apps that host your data on third-party infrastructure. GanttBoard does not.