Air Explorer has included some of the Box utilities as the lock function, the collaborators and the metadata features.

Metadata allows users and applications to define and store custom data associated with their files in Box. With Air Explorer, you can manage the metadata very easily.

In the next link, you can find information about the Box metadata:
https://community.box.com/t5/Organizing-and-Tracking-Content/Metadata/ta-p/307

Select the file you want to add or modify the metadata an click right botton and click metadata.

Then, a window opens and here you can manage the metadata of this file.

You can check more information here:
-File lock function for Box in Air Explorer
-Collaborators support for Box in Air Explorer