RMWebsec

Like a normal text widget this allows you to easily post text and HTML, but 
now you can execute PHP too! 
This makes merging with other themes easier.
!IMPORTANT! You must use tags for the code to be 
recognized.

PHP-Widgetify

Execute HTML, Text or PHP fast and easy with this Widgetify-widget.

Viktor Szépe

Execute WP-cron manually by clicking a button on the Dashboard. 
WP-cron is WordPress’ scheduler system, it can execute background jobs like plugin updates.
Manual Cron is a Dashboard widget available for every user.
If you have poorly written plugins WP-cron’s output may not be empty.
<h4>Links</h4>
Development goes on on <a href="https://github.com/szepeviktor/manual-cron" rel="nofollow ugc">GitHub</a>.

Manual Cron

Triggers WP-cron from a Dashboard widget and displays output.

PHP-Widgetify vs Manual Cron