I like the RS MD5 option but there is a problem with the string form:
currently it return a string like this: "
filename --- md5"
but most of md5 checker software using *.md5 file understand string like that: "
md5 *filename"
So if you could change this it will be easy to copy/paste and check files with an md5checker software.
A better suggestion would be adding an option to save directly to an *.md5 file