With the help of the link How Do I Install/Upgrade/Uninstall an AppExchange App, you can easily understand how to install/upgrade/uninstall the app from the AppExchange.
PS: View Mass File Upload, Salesforce file upload app, on Salesforce AppExchange: https://appexchange.salesforce.com/appxListingDetail?listingId=82cf236b-1ee8-4ea7-aebf-fd0c89fb93bd