There are few plugins for check WordPress theme submitting in wordpress.org
- Theme Check
This plugin used to check latest WordPress standards and practices.
- Debug Bar
- This plugin used to display query and debugging information.
- Query Monitor
- This plugin display database queries, hooks, conditionals, HTTP requests, redirects etc. and view debugging and performance information.
- WordPress Importer
- above plugin is import dummy data easily. to display theme all style stander.
- Monster Widget
- list of WordPress all widget.