This plugin hasnt been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.
The plugin is simple and does the job very well. Install, select which post types to display in WordPress Dashboard > Settings > Helpful and you are good to go.
The plugin has scope for growth by adding few features as others have suggested. However, it is a useful plugin as it is.
Thank you for sharing it with the community.
We need a simple dashboard just like you created the fast and simple feedback plugin for us. We really love this even we will donate some bucks but please add the dashboard to see which one is going up and doing great.