How do I check the theme / product / extension version and change log?

You can do this from the Magento admin in 2 simple steps.

Step 1. Go to WeltPixel -> WeltPixel Debugger -> Extension Version. ( If you don't have this section in your Magento admin you are using an outdated version of the WeltPixel extension).

Step 2. Check the modules that are not using the latest version.

Note: The latest extension version can be downloaded from the "My Downloadable Products section" of your weltpixel.com account. 

Step 3. How about extension Change Log? 

The extension change-log can be found at the bottom of each extension product page on weltpixel.com.