The free version is available on our website.

https://levonotion.com/products/keyframe-collection/

Collection visibility can't be animated In Blender, you can only animate the visibility of individual objects in a collection.

You can toggle the Visibility of a collection without using the Outliner.

You can toggle the Visibility of objects in a collection without using the Outliner.

The Pro Version makes it possible to animation the visibility, location, rotation and scale of all object in a collection using three buttons:
"Add Keyframe" , "Delete Keyframe" and "Clear Keyframe"

The Base Version makes it possible to animate visibility of all objects in a collection using two buttons: 
"Add Keyframe" and "Delete Keyframe"

Pro Version

Version 1:

• Options to add keyframe to location, rotation and scale
• Option to add keyframe to object visibility
• Remove animation data with "Clear keyframe button

Base Version

Version 1:

• Initial Release

Version 2:

• Toggle visibility of objects in collection.

Version 3:

• Works with current scene irrespective of "Scene" Name
• Fix blender crashing with Toggle Visibility of objects in Render
• Add collection viewport and render toggle icons change

Version 4:

• Updated to Extension for Blender 4 series and 5