Regenerate Thumbnails is one of the plugins I’m first to install when working on a development build. It essentially lets me insert sample content once, then not worry about adding more when it comes to testing imagery for different template designs.
For example when I’m coding a very basic template, it usually involves creating several templates to convert the design into a working template file, rather than creating duplicate contents for these templates rather speedily I can use the same contents outputted with different tags and styling to suit my needs. With the addition of the regenerate thumbnails plugin I can then reprocess the existing imagery to suite my needs whilst I’m carrying out a test run.
As a bonus I found that the plugin also works extremely well with the Additional Image Sizes plugin, which hasn’t been updated in quite some time but still works a charm. This allows me to create additional image sizes and through the regenerate thumbnails plugin have media within the media library have these new sizes automatically created which has been a great timesaver in the past.
As always, do let us know what you think of this plugin, or if you’ve got a plugin you can’t go without when developing in WordPress make sure you give us the heads up.