Great and useful feature!
Really, thank you for implementing this!
But I am missing a way to paste in a checksum to let it be compared and verified with the calculated one.
Maybe you could also add the possibility for verifying a file by choosing a .md5 file from your local drive (.md5 files often includes several lines with the checksums on the left and the file names on the right, if there are more than one file offered).
Also, if a checksum fits, it should show a green info text, if not a red info text