Greg Winiarski

BlackBox is symfony like unobstrusive debug bar attached to the top of the browser window.
How can it help you with development: 
1. instantly inspect global variables (GET, POST, COOKIE, SERVER) 
2. debug both frontend and admin area 
3. executed MySQL queries and time it took to execute each query (useful for finding slow queries) 
4. profiler for measuring performance of your plugins and themes 
5. errors occurred when loading WordPress page

BlackBox Debug Bar

Immediate feedback on a great majority of errors. Added a conditional red background to the Errors, and with this modification I have never miss even a notice anymore.

Thank you very much!

Essential plugin in my developer toolset

BlackBox is a plugin for plugin and theme developers. It collects and displays useful debug information (errors, executed queries, globals, profiler).

Dominik Schilling

Debug Bar Transients adds information about WordPress Transients to a new panel in the Debug Bar. This plugin is an extension for <a href="https://wordpress.org/extend/plugins/debug-bar/" rel="ugc">Debug Bar</a> and thus is dependent upon Debug Bar being installed for it to work properly.
Once installed, you will have access to the following information:
<ul>
<li>Number of existing transients</li>
<li>List of custom transients</li>
<li>List of core transients</li>
<li>List of custom site transients</li>
<li>List of core site transients</li>
<li>An option to delete a transient</li>
</ul>
Sounds pretty good? Install now!
This plugin is inspired by the <a href="https://wordpress.org/extend/plugins/debug-bar-cron/" rel="ugc">Debug Bar Cron</a> plugin.

Debug Bar Transients

Debug Bar Transients adds a new panel to Debug Bar that displays information about WordPress transients.

BlackBox Debug Bar vs Debug Bar Transients