The Box for Android app supports sharing with both shared links and collaboration.
To get a shared link, click on the "link" icon. This will open up a pop up window with the shared link url, an option to "Copy link", "Share link", and "Edit link permissions".
To add a collaborator, press the "person" silhouette icon. This will open a pop up window with two options; Invite and View. The invite option will let you add email addresses and select an "access permission level". The "View" option will allow you to see the current collaborators in the folder.