It adds these features to improve the GitHub Issue tracker directly into GitHub.com, allowing you to:
- Display issues on a task board by priority and progress
- Attach any file type to an issue
- Add estimates and view burndown charts / metrics attached to them
- +1 issues to avoid excess comments
- Improved search functionality
- Link repos together to view issues that span multiple projects
Without having to context switch out to a separate issue tracker or UI
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Disclosure - I work at ZenHub, and use it with GitHub all day :D
- Searching all issues for an organization
- Voting on issues (not just :+1:)
- Public issues for private repos
- Attaching files (repros, necessary files, etc.)
- Dependencies/links
- Priority (you can label priority but not sort by it)
- Metrics of any kind