Here is a script which lets you pick a file from your storage area, which is then downloaded by your device. After that, it reports the file size and MD5 checksum in the status columns. This is a trivial example and we expect that you will add your own actions to perform upon the file if needed.
Download the attached file to your system, then upload it to remote.it:
Upload the file you wish to send to your device as you uploaded the script, but selecting "General Purpose Content" in the dialog.
Run the script and select the file you wish to transfer, then click on "Finish".
Once the process completes, you will see the file name, size, and MD5 checksum as reported from the target Device(s):