The above code allows me to handle any filetype at all (DataHost="*.*") and will cause my application to appear as an option in the "Send" link of any other app. If you only need to handle a specific filetype you would change the second * in DataHost to the filetype you need, such as (DataHost="*.png") would only handle PNG (Portable Network Graphics) files.
In my case, since I am accepting all filetypes, I need to determine what type of file I was given and handle it appropriately. You can see this occurring in the operations with the data derived from intent (intent, action, type), which is the incoming file details and requested action by the other app. The action type gives a hint on what needs to be done with the file being sent (Send, Open, View, etc.) and the type tells you the MIME type information for the file, whether it's a PDF, image file, APK, MP3, webpage, etc. If you aren't sure what file type you need to receive, set your DataHost to *.* then set a breakpoint, debug your app and inspect the intent.type after opening the desired file.