Jakobodb

This utility plugin changes the theme of the current user to Sunrise, and uses the Sunrise color scheme when browsing the front-end, to help ensure you are viewing and editing the Development Site when making crucial changes to a site.
This plugin also adds a menu item to the admin bar to further confirm that you are on the Development Site.

Development Mode

Uses Sunrise theme on Dashboard and Frontend to visually represent development mode

Giulio Daprela

This plugin is a ‘swiss army knife’ of custom fields. It allows you to manipulate them to make it easy the testing and debugging of applications.
This plugin was built in a moment of desperation when I couldn’t access phpMyAdmin in a mu website. 
I absolutely needed to manipulate the custom fields for testing and debugging, version 1.0 was up in 4 hours. 
In the following months I realized how useful the plugin was and couldn’t work anymore without it. It had become part of my standard toolset.
Features: 
1 Read/write/delete options, user fields and post fields. 
2 Populate the field with an empty array. 
3 Insert a date string and translate it into a timestamp or vice versa to emulate specific dates. 
4 Change name to a field. 
5 Copy any field’s content to any other field (for example, option to user field) even of a different name.
You can contribute to the plugin or just study the code on the <a href="https://github.com/daprela/dapre-custom-fields-tools/" rel="nofollow ugc">Github repo</a>.

Dapre Custom Fields Tools

Works exceptionally well to assist in debugging and testing of custom fields in WordPress. Does it well, and saves you time.

Does what it says on the box

This plugin is the 'swiss army knife' of custom fields. It allows you to manipulate them from the dashboard to make it easy testing and debu …

Development Mode vs Dapre Custom Fields Tools