Hello 
community,
This is a feature request that has been around for some time. @victorbrac originally asked for this feature for here, and @crduggin recently brought it up for the Revit plugin here. We also received a few private messages about getting a notification when a new version of the plugin is available. So here it is!
Revit plugin
In the Revit plugin (version 2.154.1 or newer), you should see a new button that allows you to check if a new version is available. We also check for the availability of a new release on Revit startup, and you will see a red exclamation mark next to the button if a new release is available.
Rhino plugin
In the Rhino plugin (version 1.31.5 or newer), you will see a notification at the bottom of the Rhino Pollination Panel. Similar to Revit, we run a check at the Rhino startup.
You can use the PO_CheckUpdate command to get more details about the available version.
Next steps
The next step is to provide better documentation about the changes between the releases. Until then you should check the announcements to follow the new features and fixes.
Thank you, and happy Pollinating!